Sunday, October 26, 2014

Catherine of Lyonesse




Is that a gorgeous cover, or what?

Considering that the book has now been out, in the UK, for about ten weeks, it is high time and then some that I highlighted it here, (But possible good news on my sluggish posting - fingers crossed! - below.)

How it is selling, as yet I have no idea. On Amazon, not very much, but I am told that it is not a "major channel" in British trade publishing sales, and the fact is that a first novel depends heavily on old fashioned sales off the bookstore shelves.

A public acknowledgement and thanks is due - and overdue - to Tamora Pierce, official Friend of this Blog, and the faerie godmother of Catherine over many years. Also to blog reader and occasional commenter Anita, who originally worked out the genealogy at the front of the book. But I assert sole credit for mistakes.

I should also tip my hat to a reader, 'Gracie,' who posted a wonderful reader review at Amazon. Five stars are always wonderful, but her elegant and insightful comments even more so. Courage and panache, indeed!

And also a tip of hat to a couple hundred of Tammy's fans who responded to her wonderiffic Goodreads review by putting CoL on their to-be-read lists.

Finally, I should say that while the ebook version is not currently available in the US (pending a hoped-for US edition), the paperback version can be ordered from anywhere.  :-)


Biochemistry Note

As I've noted here previously, the life sciences tend to get relatively short shrift in space discussions. I rarely remember life support ecology getting anything like the detailed discussion given to shiny stuff like propulsion systems.

But these things matter, as I have been reminded by being diagnosed with diabetes (type 2 - the kind that doesn't require daily insulin), AKA the American disease, the result of a lifetime of bad dietary habits coming back to bite me. I seem to be responding well to treatment, but one effect of the disease, relevant to this blog, is fatigue.

So, as treatment progresses, I hope to overcome that and start posting here more frequently.


And a Return to Space

Those loyal readers who still drop by here from time to time will surely (?) be glad to hear that I have lately been reading and thinking more about space again. I hope to post some of the results here soon. Meanwhile, I encourage everyone to (re)visit the wonderful Atomic Rockets website, which has been greatly expanded over the past few years even as this blog went relatively quiescent. 

Talk to you again soon!

457 comments:

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Cordwainer said...

Good rebuttals to Tony's comments.

My issue with drones is that they are rather expensive combat options currently. Most drones that do operate are in roles where the cost is worth the benefit or the cost is lower compared to protecting a soldier from the same threats in combat. While drones and robots are getting cheaper and their capabilities are increasing you have to take into account the cost of creating a robot that can do all the things that a human can do and do them well, particularly when it comes to the fluid and asymmetrical environment of ground combat. Naval and aerial drones are probably going to be easier to develop for a large range of tasks, ground combat drones I imagine will require a bit more development in the area of AI.

Anonymous said...

RE: Using an explosive to generate electricity to power a directed energy weapon vs just using a missile

I am trying to understand the basic premise Energy at work here. Since its suggested the Missile will have the prohibitive mass, not the Energy Weapon.

The Energy Weapon has the weapon itself. It has the heat radiators. It has sophisticated aiming equipment since it has to do all the targeting from the apex distance.

Now in order to power the weapon a bomb goes off of some kind. At some significant loss you get energy for the weapon which then is fired at the target. The weapon itself has something much less than 100% efficient conversion as well.

Assuming the bomb is chemical in nature, it is working at around the same energy for mass as the missiles propulsion system.

Lets say for sake of example we have an explosive power system that converts chemical action into electricity at 50% efficiency. This then is used by a laser that is 50% efficient. So overall efficiency is 0.5*0.5 = 25%

Keeping it simple, a 1000 Energy Units of Bomb gives you 250 Units of of laser.

In the missile though 1000 Energy Units of bomb gives you much closer to 1000 Energy Units of Propulsion. The Missile therefore will be relatively less massive.

Then you also can leave off the radiators, simpler targeting (since the missile is a lot closer to its target on the final approach, etc), and the entire BF energy Gun.

This is obviously why the Nuclear Bomb pumped Lasers come up. Since they have vastly more energy for a given mass than the chemical system.

Although you could use a nuclear bomb to accelerate a missile too.

--
NH

Anonymous said...

The Robot could be semi-autonomous. Where it has a list of basic functions but is commanded by a drone operator. So /Someone is shooting at me!/ Might get broadcast. Operator clicks "Shoot Back Confirmed" and the Robot fires back using its programing.

This sort of system was what I had in mind earlier in the thread where I suggested that Robot would lack the flexibility of well trained soldiers like Special Forces. It might be great at "Go down this street and shoot at Identified bad guys designated A-F." or "Patrol Zone 34, eliminate all resistance encountered." But it will be bad at many of the things that experienced soldiers do on a routine basics.

It will not be as smart as a human, no matter how good the programming. Even a drone will have some situational limits a human that was there in person wouldn't have.

--
NH

Anonymous said...

I am not sure how "Ground Robots won't be used for sake of conventions" coexists in the world of "If you call it a Drone you can use it where politically you could not use an Attack Aircraft that has a pilot."

I think the test case for will they use Ground Drones/Robots is already happening every day.

And the longer the Legal/Political fiction that a drone isn't an attack aircraft continues to find traction the more I am convinced that is the direction we are heading.

--
NH

Cordwainer said...

To answer Anonymous regarding the use of missiles versus other chemical explosive weapons.

Can't argue with hypothetical math but people use inefficient weapons all the time. Hell a gun is an inefficient in terms of its physics compared to a rocket but you don't see to many people carrying Gyrojets, Anonymous. I think you are over thinking or oversimplifying things.

Chemical energy is simple to manufacture and easy to control in terms of heat because it acts in terms of fluid thermodynamics. As opposed to a solid state laser where heat has to be directed away by a radiator or working fluid in the case of a gas-dynamic laser the explosive itself can act as the working fluid.

As to aim one could use an weapons array approach so you don't need to aim a whole lot you just wait for the missile to pass over and trip your sensor and then ignite your laser, the laser moves at the speed of light so the only time lag is the time it takes for the chemical reaction to produce an electrical impulse. With a missile you have to launch and guide that missile to it's target and the missile will take much longer for it to reach it's target. If the missile has it's own sensors for guidance then those sensors will likely be cheap or will rely on relay with sensors on board the ship. Such sensor systems can be fooled or jammed.

Guns firing inert missiles might very well be more effective than lasers for point defense and I tend to think that point defense would likely center around flat panel IR laser brooms and superimposed guns like Metal Storm which could be conformed to the shape of the ship, thus giving wide area defense and redundancy without a lot of moving parts. While something like the chemical powered weapons I described would be used more as "offensive battery" weapons.

As to why missiles might be more mass prohibitive is due to these reasons:
1. You need more of them to do the same job in terms of point defense of close combat compared to a few lasers in turrets.
2. For medium to long range combat a guided missile can get really big due to the fact that space is a much more vast combat arena than little ole Earth. It also has to carry its own guidance systems and possibly it's own anti-missile, anti-jam, anti-flak systems.
3. Which brings up another problem with seek to kill weaponry in that in space for any kind of explosion or shaped charge penetrator to work you have to get very close. That means that your hot flaming rocket is a big flaming target for much of its path to its target.

Of course you can always have a multi-mode missile that accelerates toward its target and then coasts most of the way in before making a "Hail Mary" attack acceleration. You can also arm your missile with a laser or hyper velocity projectile to increase the kill range and lower the time to target.

Laser, guns and missiles have different ranges and applications where they excel at. Unfortunately, using conventional chemical rocketry I tend to think that the range at which missiles are useful over lasers and guns is a small one. A missile carrier in a future space war environment is more likely to be closer to a drone carrier in my opinion, and just like modern aircraft carries they are going to be expensive and technologically advanced man-of-war type craft and not something a "low tech" or "low income" space navy would use.

Cordwainer said...

Laser, guns and missiles have different ranges and applications where they excel at. Unfortunately, using conventional chemical rocketry I tend to think that the range at which missiles are useful over lasers and guns is a small one. The caveat being a small difference in range in terms of space combat. When your dealing with planetary gravity and atmosphere a rocket obviously has a range advantage. In space though guns can be used in a shotgun effect to do many of the same tasks rockets would do and lasers are going to have a lot more reach due to lack of atmospheric attenuation and both a greater availability and need for electrical energy. Yes we have gotten by with Spartan power systems for our recent manned and robotic space missions but as we head out into deep space having a more robust power generation system makes a lot of sense both for creature comforts and the survival of the crew.

Tony said...

Anonymous:

"Re: Tony further explaining his take on War Conventions..

Let me see if I get this right, you suggest:
1. War has always carried personal risk to combatants
2. The acknowledgement of said risk has contributed to the development of war conventions.
3. Thus war must always continue to carry such personal risk in order to preserve the conventions that came about due to step 1.

Where does the fact that for most of history it was impossible to remove the human from the battlefield come in?

Now that it is becoming possible, I don't think they will keep robots off the battlefield for platitudes sake.

Why exactly can you not surrender to a drone or a robot? Surely it is possible to program a robot to accept a surrender if you can program it to Shoot a machinegun."


Simply put, you're failing to separate what might be technically possible from what is humanly acceptable. The whole point of talking about war conventions is understanding that using any given technical capability and prudent action are not always the same thing. I'm not that war conventions prevent anything. I'm saying that failing to observe conventions can -- and usually does -- causes whatever retaliation seems most expedient.

In the case of robotic combatants, the perception among opponents will be that a power doesn't GAS about the reciprocal nature of risk in war. Heck, we already see that with overwhelming air and mechanized power. Opponents confronted with the impossibility of prevailing under conventional conditions resort to assassination, insurgency, and terrorism. Use of robotic proxies for real human involvement will only exacerbate that phenomenon.

And, to return to the overall ethical question, when one removes the risk from war, one doesn't engage in war, but predation. Predation may be what a power wants to do, but that's not what it should do -- not if it doesn't want to paint a target on its back. Think of what you know about the history of the last hundred years, and you may find a few examples. Or maybe you recall the Melian Dialogue, and what ultimately happened to Athens...

Eth said...

What drives guerilla warfare/terrorism isn't technical superiority but vast differences in strength - whatever its origin.
Washington successfully used guerilla warfare against the British because he knew he couldn't win in conventional battles, even though both sides had similar technical level (then he tried anyway because he couldn't stand such an ungentlemanly, dirty way of fighting and took serious blows).
Same can be said about Shinobi and many others in History. Even in basketball:
http://gladwell.com/how-david-beats-goliath/

This doesn't stop anyone for trying to have overwhelming power, whether or not it drives their opponent to unconventional, guerilla tactics. In fact, if you look at modern Western militaries, they even adapt and use unconventional tactics: use special forces, arming and training locals, assassinations, PSYOPS...

If they can get more power through technical development, they do. If they can get it through drones, they will.
Conventions are only created (or at least, enforced) when both sides realize that they have more to loose otherwise (and that's often after a first, devastating use). Nerve gas, nukes, possibly uncontrollable bioweapons, space weapons assuring mutual destruction of all space infrastructure...
Even then, it's only if both sides consider they are directly affected by it. Look at anti-personnel mines (the modern kind, that are meant to rip your legs off instead of killing you). Most civilized countries signed a treaty banning their production and use because of the political cost to do otherwise, and because they don't want their soldiers to have their legs ripped off. The US (last time I checked), where political costs of angering anti-personnel mine manufacturers is bigger, didn't.
The fact that it is an abominable weapon that is devastating for civilian populations for decades and ruin entire terrains is irrelevant in both instances.

Similarly, a convention against drones would only be passed if the drone users have a bigger cost otherwise. Politically, the cost of losing soldiers is bigger, so it won't happen that way. Terrorists will appear anyway because of the difference in strength, so it won't cause it either. In case of conflict between two drone powers, it won't change much given how mechanized such war would be already.
What may happen is a convention to prevent humans to be out of the loop. The political cost of having drones making autonomous lethal decisions ("killer robots") will hopefully be big enough to be forbidden. Or maybe it will happen because autonomous drones will make Blackwater look like the GIGN regarding civilians, and drone powers will realize that both sides will loose more whatever the result of the conflict.

However, getting a drone power like Iran to respect such conventions is going to be tricky, to say the least.

jollyreaper said...

Concerning the human part of war, we've pretty much removed leaders from consequences since kings stopped leading from the front. The last English king to die on the battlefield was Richard III. We're not about to see Elizabeth II wading out into the field of glory with a plate metal bustier, chainsword in one hand, bolter pistol in the other. Leaders have always been insulated. They don't care who dies.

There might be an argument that popular support for a war could fade if the average voter's children could end up drafted and sent overseas to die. The rich could get deferments for their fortunate sons and these days with a volunteer force you only get patriots and poors. It's not a representative cross section of society and we as Americans don't take enough casualties for it to actually register. Bear in mind western societies were once able to shrug off 10k dead in a day as the price of doing business. I don't think the blood cost really registers with the stubbornly determined until you start talking a literal decimation of the total population.

In other words, if all we're counting on to keep our leaders in check is flag-draped coffins coming home, we've already demonstrated that it doesn't work. More robots on the battlefield aren't going to make things any worse than they already are. It could actually improve things since we can always set a robot at a traffic stop for a restricted ROE, one we couldn't count on for a scared 18 year old infantryman with an itchy trigger finger.

jollyreaper said...

Similarly, a convention against drones would only be passed if the drone users have a bigger cost otherwise. Politically, the cost of losing soldiers is bigger, so it won't happen that way. Terrorists will appear anyway because of the difference in strength, so it won't cause it either. In case of conflict between two drone powers, it won't change much given how mechanized such war would be already.
What may happen is a convention to prevent humans to be out of the loop. The political cost of having drones making autonomous lethal decisions ("killer robots") will hopefully be big enough to be forbidden. Or maybe it will happen because autonomous drones will make Blackwater look like the GIGN regarding civilians, and drone powers will realize that both sides will loose more whatever the result of the conflict.


Agreed with the terrorist/guerrilla tactics arising from disparities in strength. You've got basically two types of insurrections, the kind trying to drive colonial occupiers out (they can give up and go home) and the kind against domestic oppressors (who are fully invested in staying in power.) Guerrillas really have a hard time succeeding. Much of the time they will remain a constant presence that can never be eradicated but also have no hope of winning. Such a system can remain metastable for quite a while. See the FARC in Columbia.

Against a strong state, rebels can't really win. The internal security apparatus is like an immune system and will wipe them out. Only when the state grows weak and ineffective can rebels have a chance of defeating it, like a person with a weakened immune system being killed by a simple cold.

Where I think drones really have a chance of taking terror to the next level is political assassination. Today we are zotting supposed terrorists with $4 million Predator drones using $100k hellfire missiles. In not too many more years I can imagine American political leaders getting zotted by drones. I have a feeling that these things are going to get locked down harder than explosives and machine guns. Licensed professionals will be able to operate drones but private citizens? Hell, no. That won't stop the technology from being developed overseas, it'll be too damn cheap. Image recognition, able to read biometrics from a target's gait to identify a specific individual, it doesn't take much extrapolation. The president going anywhere is already a three ring circus. Anywhere he is outside the Secret Service has to secure all vantage points that would be useful for snipers. Throw in the risk of drones making kamikaze runs out of the blue and I think we'll see the end of outdoor activities. I predict we'll see a Boston Marathon bombing with off-the-shelf quadcopters and homemade pipe bombs, just flying into a crowd to cause random casualties and suddenly we'll see billions poured into drone defense. Hunter-killer drones to patrol the perimeter, some adaptation of anti-RPG systems for terminal defense of targets.

After the first few successful attacks I don't see many VIP's dying, just like it's rare to see successful assassinations today, but the security constraints they'll have to operate under will be so much stricter. Right now they're mainly concerned about lone nuts with guns. Drones mean they'll have to be even more paranoid. I'm sure that paranoia will spill over into the decisions the VIP's make.

jollyreaper said...

Now how could I be wrong about this? Well, the development of portable SAMs (MANPADS) would make it seem like all world leaders are now vulnerable to getting shot down. There are supposed to be tens of thousands of them available on the black market. How many incidents of terrorism have there been? Only a handful.

http://en.wikipedia.org/wiki/Man-portable_air-defense_systems#Against_civilian_aircraft

Only one political assassination appears to have been successful, killing the Rwandan president in 1994.

I have no explanation for why there are such low occurrences. I suppose the problem for a terrorist wanting to blow up an airliner is that they are too high to hit when cruising so you can only target them near airports. The people you want to kill are in countries where smuggling in missiles could prove difficult. Terrorists might not have access to the channels drug smugglers use since the drug smugglers don't want to borrow the kind of trouble that would come with a successful terrorist attack.

What I can see happening is drone strikes against political leaders will become as verboten as any other conventional assassination attempt that could have been attempted in the 20th century and was likewise avoided for obvious reasons. However, the cheaper the tools get, the less likely the users are to adhere to sensible ideology. The logic that keeps Pakistan and India from going nuclear might not play out for a terrorist group with a nuke.

Anonymous said...

RE Cordwainer and chemical fueled lasers vs missiles.

A firearm is actually extremely mass efficient for what it does. And the process used Chemical => Kinetic is basically the same for firearms and gyrogets. The firearm just has all the reaction at the same time. While I do not know the relative efficiency of either, Firearms seemed to be much more effective.

It is telling that in order to make an electrically powered kinetic competitor to a firearm you would need a giant backpack battery, capacitors, etc. And in the end you would come out behind in fire rate and other things.

It is similar to the Laser vs Missile argument on the space craft.

I am not sure where range comes in, the missile would have a pretty massive range if its already in orbit, assuming it had sufficient Delta V.

Speed I can see being a big consideration. Its hard to beat the Speed of Light after all. But maybe you don't need to. Especially if your opponents don't have much power to spare either.

Some of this might be our relative assumptions. I am assuming Space warship will descend from modern space craft, since the realities of space dictated how those are built.

If you assume something more like Submarines in space! Where ships are heavily built and all have big nuclear power plants, I imagine you can power the Laser.

--
NH

Anonymous said...

RE: Tony and War conventions

I think my misconception might be from the tone you are trying to convey. It reads like you are clearly stating Ground Combat robots will not happen.

However the actual content of your reasoning comes off more like it would be a bad idea to have Ground Robots.

In the case of the former I would have to say you haven't made your case.

You have made several very good points as to why it would be a bad idea from a sort of philosophical angle. But at the same time you say the US may have already crossed a comparable line with its current force superiority.

Which leads me to again wonder why would they not go ahead use the robots.

You could plug in most of your reasoning to argue against Drone Attack Aircraft, yet they clearly exist and are being used regularly.

--
NH

Anonymous said...

I think the retaliation argument is actually a non starter. We currently have a nuclear power waging a proxy war with its neighbor, after annexing a portion of its territory.

The retaliation against Russia has been anemic. It is breaking all sorts of "conventions" of the Post World War era. Its so bad many pretend politically the sanctions are ruining their economy and conveniently ignore the price of oil is the actual driver.

Conventions are broken often. When Nazi Germany switched its strategy of bombing military targets for bombing London's civilian population instead it was violating convention.

The "punishment"? Later in the war the Allies violated the same Conventions to a much bigger degree.

When the Nixon administration started bombing unaffiliated countries in the Vietnam War he was breaking Conventions. The Punishment? Some liberals still will heckle Kissenger.

--
NH

Cordwainer said...

Well, let's just agree to disagree then Anonymous but one last nod to why lasers would be practical weapons in space warfare.

"You could plug in most of your reasoning to argue against Drone Attack Aircraft, yet they clearly exist and are being used regularly.", and
"Which leads me to again wonder why would they not go ahead use the robots."

We already have laser weapons on the battlefield. They clearly exist and are being used. So why wouldn't you use them in space. You need to make an effective counter-argument as to why space warships will descend from modern aircraft and whether that even makes sense when we have weapon systems like the Boeing YAL-1.

Cordwainer said...

Thought this might be interesting since the original subject of this blog was about biochemistry and we seem to be heading into discussions on AI.

http://www.msn.com/en-us/news/technology/eve-the-robot-scientist-discovers-new-drug-candidate-for-malaria/ar-AA92y3d?ocid=DELLDHP

Anonymous said...

I was more thinking that many armed spacecraft will lack sufficient on-board electric power to use Lasers and other Energy weapons. Using a chemical fired explosive to power a laser seems very mass inefficient which is a big no no in all space craft to date.

On earth the Mass limitations are far less, and heat removal is comparatively a cinch.

The warships I have in mind are much closer to Apollo than Andromeda.

Basically Lots of Electrical Power = Lots Mass and Mass kills performance. Particularly since this mass is on the wrong side of the Mass Ratio Line.

I can see where there might be some craft with larger power sources of course. And those would probably have electrically powered weapons of some kind. Lasers being a good choice probably. On craft that don't "move around" all that much.

--
NH

Cordwainer said...

Does it really kill mass ratio though. Any space warship is either going to be a fuel hog or very fuel efficient. That means that it will need to either carry a large power generation plant to power some kind of fuel efficient propulsion system(fusion, plasma, ion etc.) or it is going to carry a lot of fuel to mass in which case you would be best off carrying a fuel that can have a dual use as a fuel or power source for weapon systems. In either case the less tendering, more automation and fewer moving parts you can employ for a given weapon system is what is going to determine mass ratios. Warships will likely not have large crews(if any) and by their very nature will be pretty massive with a large payload capability.

For the reasons I mentioned before your more likely to have drones over missiles and gunboats over space fighters. So if your going to have a large aircraft carrier as the center of your fleet then it doesn't make a whole lot of sense to build missile cruisers when destroyers and frigates will do the same job protecting your aircraft carrier and your carrier can do most of the same jobs that your missile carrier can. This is why you don't see anybody building battleships anymore and you see battle cruisers being replace by light cruisers and littoral "gunships" or destroyers.

Space is more an ocean than it is an aerial like environment. Sure you can move more freely in multiple directions but you can't zip around making crazy turns and maneuvers like in Star Wars. Why us space more like an ocean, you may ask?
1. Space is vast. Distances in space our on the scale of weeks, months and years with our current technology.
2. Space is a mostly low gravity environment so things that stay at rest or in a certain trajectory tend to stay that way. If it takes you weeks to get anywhere that leaves you precious little fuel to perform evasive maneuvers and a throw away weapon like a missile or drone would have the advantage in changing course.

Thus you need effective point defense and big honking power hungry lasers are about as effective a point defense as you can get. Also, most military lasers already use gas-dynamic systems to power them or augment their destructive capability(look it up). Chemical energy in the form of batteries is one of the most efficient methods in terms of storing energy that we have and explosive pulsed energy can be just as efficient in producing large amounts of electrical energy. I hate copy and pasting Wikipedia as a source, but this is sort of general information and some of the links on pulsed power might be of interest.

http://en.wikipedia.org/wiki/Pulsed_power



Steady accumulation of energy followed by its rapid release can result in the delivery of a larger amount of instantaneous power over a shorter period of time (although the total energy is the same). Energy is typically stored within electrostatic fields (capacitors), magnetic fields (inductor), as mechanical energy (using large flywheels connected to special purpose high current alternators), or as chemical energy (high-current lead-acid batteries, or explosives). By releasing the stored energy over a very short interval (a process that is called energy compression), a huge amount of peak power can be delivered to a load. For example, if one joule of energy is stored within a capacitor and then evenly released to a load over one second, the peak power delivered to the load would only be 1 watt. However, if all of the stored energy were released within one microsecond, the peak power would be one megawatt, a million times greater. Examples where pulsed power technology is commonly used include radar, particle accelerators, ultrastrong magnetic fields, fusion research, electromagnetic pulses, and high power pulsed lasers.

Cordwainer said...

Also if overall efficiency of a explosively powered laser is 25% by your off the cuff calculation then that is a lot more efficient then many methods used to power lasers.

Geoffrey S H said...

"So if your going to have a large aircraft carrier as the center of your fleet then it doesn't make a whole lot of sense to build missile cruisers when destroyers and frigates will do the same job protecting your aircraft carrier and your carrier can do most of the same jobs that your missile carrier can. This is why you don't see anybody building battleships anymore and you see battle cruisers being replace by light cruisers and littoral "gunships" or destroyers."

Sorry to quibble with your analogy, but the increased size of destroyers makes them essentially missile cruisers -10,000 tons is even approaching pre-dreadnought tonnage- and much more likely to survive a missile hit. I'd say that the short 50 year period when surface vessels were 15,000+ tons is an abberation and a distraction from the fact that Arleigh Burke Class destroyers have serious staying power. Factor in the need to make said ships at least somewhat capable of defending themselves against aircraft, and you have a system akin to the 18th century navy division with modern adjustments (frigate : battleship/large destroyer : aircraft carrier).

Your point still stands though. I would argue that if it cannot be recovered, then a space-drone would essentially be a missile (unless you wanted a common hull to outfit for point-defense, probes and anti-shipping roles).

Anonymous said...

In an ocean you can use the ocean to push the ship. That's what the prop does. All that reaction mass, for free.

You don't get that in space, and to add insult to injury you are going farther too, Need a whole lot of Delta Vee.

Then to make things worse you cant use the water to cool your spacecraft either.

If we we talking about putting a laser or some other electrical powered weapon on a Ocean Vessel, I would be right with you. Not that bad at all.

An airplane or a truck even, same thing. The truck can push against the ground. The Airplane can use the air. Both are air cooled.

They are no where near as mass limited as a spacecraft is.

The spacecraft though needs to bring all its reaction mass with it. And the more mass its carrying, it needs even more reaction mass. It is a vicious circular logic problem.

So yes the mass hurts the mass ratio. And the mass ratio will matter a lot. This is the rocket equation in action.

Sure we could argue for some electric drive, but the thrust performance will be abysmal. And unless something drastically changes the power for mass of even nuclear reactors in space will make the thrust performance poor.

All electric drive systems are high power in, low thrust out. It will be difficult to even make a spacecraft with no Laser have much performance in terms of thrust.

Then add the Laser and all these energy storage devices you want to incorporate...

Fusion perhaps .. but that's likely a very long way off. It doesn't even work on Earth Yet. Let alone a mass efficient space based design.

We have had fission reactors for 70 years and don't have a mass efficient space based design for plentiful electric power. At least not in the MW range.

I am assuming we'd want laser in the hundreds of Megawatts here. So lets say you have a 10 MW Nuclear reactor on your ship. And you had in some thin-film capacitor system that is relatively low mass that lets you store the energy equivalent to a 200 MW power up. Then we need radiators, lots of them. For the reactor, which is going to produce something like 20-30 MW of heat.

Then you have some 100MW laser that is impressively 50% efficient. You can fire it once every 20 seconds.

Your propulsion system is some plasma drive but at 10 Megawatts, which is a pretty big space reactor really, you have very little thrust, You are going to be in the centi-gee acceleration range probably.

Maybe someone really refines all these technologies and gets a Ship design together that can pull 0.1 gees and fire once every 10 seconds ..

So sure, maybe some of your ships follow this model. But most of your "fleet" ... Why? The electricity demand is the killer. Use some thermal propulsion of some type and missiles.

Its a similar problem as hand lasers vs guns really. You can give a soldier a gun that weighs a few pounds and is very effective at killing people, Or you can give him a comparable Laser with a 200 KG backpack power source ..

Sounds bad. Okay now get both soldiers to run a marathon first ..


--
NH

Anonymous said...

Oh and the nuclear powered laser ship can't thrust and charge up to fire at the same time. Which given its terrible thrust performance probably isn't a deal breaker.

--
NH

Anonymous said...

Basically the idea that the bulk of a Space Navy will consist of vessels that have Massive Systems to provide electrical power when they only need said power for one of the potential weapons systems available seems an odd design decision.

A Chem-fuel or NTR equipped craft will have a much better capacity to quickly change orbits near a planet, in this case be far more nimble.

--
NH

Geoffrey S H said...

I drew a chem-fuel craft some days ago. It fires guided shells, has a single habitation ring (non-rotational) for 2 shifts of 5 crewmember each and is held together with guy-wires so as to be conservative on mass. No large scale reactor. Is this what you had in mind?

I admit the drawing is extremely poor as I knocked it together over about 4 hours, but I hope it looks something like what you envisioned.

Geoffrey S H said...

http://gs78.deviantart.com/art/Solid-core-booster-Gun-Raider-concept-508881907

Aaand I forgot to post the link! Ooops. Apologies.

Cordwainer said...

I agree that heat is a killer in space, I would think that is going to be an issue whether you use energy weapons or not.

Life support and any chemical driven system that is uses for prolonged periods of time is going to need heat radiation, liquid or cryogenic cooling.

Lasers don't necessarily produce a lot of waste heat either. It depends on the type of laser being used and the type of radiation wavelength the laser utilizes. Gas-dynamic lasers by their nature would utilize adiabatic cooling similar to a droplet radiator as part of their population inversion medium. An explosive gas dynamic or "spark gap"(ignitron) pulsed laser could conceivably be designed to exhaust heat through rapid expansion of gases. Laser diodes, fiber disk and dye lasers can be made to operate very heat efficiently in certain narrow frequencies.

Missiles and guns would produce heat as well when fired rapidly. The heat build up and temperature fluctuation in vacuum is going to much larger than in a denser medium as Anonymous(possibly Eth?) has noted. While there are methods where exhaust gases could dump that heat into space more effectively, one could use those methods for lasers as well. Also one should note that those aforementioned methods would require protuberances in the form of hardpoints or weapon bays from your spaceships hull that you may not want due to increased mass from gantry doors, gimbaled launchers and armored turrets(not to mention increased sensor profile and compromising of structural integrity)

Warships in space are unlikely to be wispy tension strung things and more likely to be sleek solid monocoque or spaced hulls where your weapons and radiators are separated from your fuel, water, coolant and crew compartments at the center. Fuel and coolant will be stored in this center hull and be pumped out to the "outer" hull where your "hot" stuff is located.

Now yes if we are talking about a largely civilian navy like a merchant marine where commercial vehicles make up the backbone it would make sense to have more specialized vessels perhaps with your merchant marines being outfitted with guns and missile pods along with the occasional "drone" carrier and its retinue of laser gunships to provide point defense and act as naval cutters when acting in a "coast guard" or policemen capacity.

The point where you start building real navies though I think the idea of a "cruise missile in space" sort of loses its edge over big honking laser gunships though. Once you have the tech to build a laser gunship with even a fair amount of propulsion capability(and we are talking about ploddingly slow laserstar-like) then the window where such "cruise missiles" are useful gets smaller. Unless you also have the tech and the money to devote to building sub-torch missiles.

Geoffrey S H said...

"Warships in space are unlikely to be wispy tension strung things and more likely to be sleek solid monocoque or spaced hulls where your weapons and radiators are separated from your fuel, water, coolant and crew compartments at the center. Fuel and coolant will be stored in this center hull and be pumped out to the "outer" hull where your "hot" stuff is located."

So... basically a cylinder with some heat radiators and an engine on one end and a small laser lens poking out the other end? Do I have you right there? Dang, that would be hard to draw... so little detail and a side-on profile that is essentially square-ish... Ugh.

Anonymous said...

The window I am discussing is basically between Lunar Orbit and LEO. As you were worried about the KKV debris effects I thought that was the same window. Or an analog on some other planet.

Missiles take their heat with them. Thermal drives (chem and NTR) exhaust a lot of their heat with expelled reaction mass, neatly solving that problem.

Of course a more simple ship will still need radiators, but it is a matter of scale. You wont need anywhere near the mass of radiators the Laser Battleship does since the Laser ship produces a lot more power. And the Laser will always produce more heat than the power of its beam, regardless of the design, you can't win in thermodynamics.

Geoffry's idea is closer to what I am thinking, although perhaps the ships are just drones. No particular reason for the crew to be on the vessel. Unless you need it for dramatic purposes.

As to the wispyness or sturdiness; physics determines function, and form follows function.

I expect the typical space combat craft will still be fairly fragile, except for perhaps the front whipple/combat shield. Hyper-velocity weapons, High Powered Lasers, these aren't things you are going to fight off with all around armor unless you have a reactionless drive. Even the armored combat shield will be a compromise, and limited in scope depending on how much mass you could spare into such a luxury.

So a sort of lightly built, forward armored(to an extent) Missile Boat, capable of operating from LEO to Lunar Orbits and destroying other vessels. The last missile could be the ship itself if necessary but that wouldn't be the standard function.

Maybe they carry a deployable Mirror made of a low mass material to focus a Laser from an orbital or Lunar station. A way to augment their firepower and combat the Laser Battleships of the world.

As to what it might look like. Not much different than something out of Apollo. Maybe Skylab if you are going to have a crew.

It will look newer of course, but realistically not hugely different. Add a thrust frame, strap on some propellant tanks and Missiles, a RTG and some small solar panels .. and the shield out front.

No Spin Hab, No Nuclear Reactor, No auxiliary craft, No Space Marines, No frills, bells or whistles. Its sole function is to kill undesirable spacecraft within its area of operation.
--
NH

Anonymous said...

So... basically a cylinder with some heat radiators and an engine on one end and a small laser lens poking out the other end? Do I have you right there? Dang, that would be hard to draw... so little detail and a side-on profile that is essentially square-ish... Ugh.
-----------------

Or perhaps a cigar shaped/submarine with holes/empty space in the hull for the empty bits with radiator wings.

Laser at the front and a electric drive at the tail.

Though really with the added mass and lack of fragility, this might be a more distant type of design, many hundreds of years in the future. Since it would really would want for some sort of fusion quasi-torch type drive to handle the added mass of the hull, radiators and power generation.


--
NH

Tony said...

A few comments on proceedings of the last few days.

Robotic and war conventions:

First off, on a something a little meta, but it was brought up and expected to be taken as a given: the modern US military consists of patriots and poor people. Once again, we are fed the life-as-cliché worldview. People join the service these days for the same reasons that they always have. They join for economic and patriotic reasons, to be sure. But they also join out of a sense of service, a quest for adventure, or just to test themselves against a system of hard boundaries. The service is actually pretty representative of the country at large, except for a very small, elite slice -- and all of the young smartasses that think they know better.

WRT war conventions and robotic combatants...

Yes, it's true we can't retaliate against Russia. But that's because it's a nuclear state and we're a nuclear state. In that case the convention is that you don't mess with each other, as long as nobody's existential imperatives are threatened.

Where it's us against terrorist groups and insurgents are concerned, not so much. They are free from nuclear retaliation, and consider us the violators of convention.

Yeah, our air power and mechanized superiority already put us in that position. And it has already also put us in the position of really ignoring conventions other civilized states want. It's not because ordnance manufacturers want contracts (more life-as-cliche) that the US has not ratified the land mine treaty. It's because mines can be a significant part of our conventional force structure when facing significantly larger enemy forces. Robotic combatants just close us further into that box, just with informal expectations about war, not the formal ones.

Space warfare;

There's hardly any point in arguing it, since it all depends on technological and economic assumptions. Define a context, and the imperatives of that context lead you to whatever conclusion they lead you to. It's all subjective.

Geoffrey S H said...

"Geoffry's idea is closer to what I am thinking, although perhaps the ships are just drones. No particular reason for the crew to be on the vessel. Unless you need it for dramatic purposes."

I should point out that that design is for a rocket-punk setting I have in mind, hence the dated squarish look (and the need for a crew, its computers are essentially 1950s IMB standard).

I would be interested to see what a drone spacecraft would look like. What shape/size would the computer module be?

Anonymous said...

Re Tony,

So where does that leave the large nuclear state that wants to use ground combat robot/drone soldiers ..

Able to do it if they want to.

--
NH

Anonymous said...

Re: Geoffrey

I would be interested to see what a drone spacecraft would look like. What shape/size would the computer module be?
------------
Not much bigger than a breadbox perhaps .. Or maybe a college kid's fridge.


Something like this?
http://i.ebayimg.com/00/s/NDU0WDUwMA==/z/fKEAAOxyyFhTde~Q/$_32.JPG

Or this ..
http://plcbangladesh.com/wp-content/uploads/2014/05/abb-ac500-plc.jpg

Or this ..
http://www.spxdaily.com/images-lg/technician-threads-wiring-ashf-satellite-lg.jpg

You would need control runs, wiring, actuators at the things the computer controls of course. Though you would have those with a human control as well.


--
NH

Anonymous said...

I am pretty sure I read the reason we haven't joined the Land Mine ban is because the N Korean army outnumbers the S Korean army by a fair amount. Add in that for a large number of years we included the Chinese in some assumptions (since they were present the first time).

To prevent S Korea from being overrun .. which almost happened twice during the Korean Conflict .. The strategy calls for land mines.

Signing a Land Mine ban when you have no need for Land Mines as a strategy is a lot easier than signing it when you see a need for them.

Probably the same would apply to robot/drone ground combatants.

--
NH

Cordwainer said...

Well Geoffrey, modern rockets aren't exactly beautiful either but they are functional.

Few weapon systems in our modern era are fragile things. They have to have sufficient survivability to be effective on in the rigors of battle. Space ships by their very nature travel in a dangerous environment and have to be able to survive vacuum, radiation, meteorites and space junk. Sure a missile bus that can be launched into orbit would have advantages against other forces in space and most likely orbital only battles are going to look very different than battles between planets or say Earth's satellite. Also, a lot of NEO combat will likely rely on artillery and siege tactics as opposed to fleet tactics.

Space Opera like fleet battles will likely be something we would see much further in the future and even then they would likely have limited application. Anonymous, your design would be an excellent design for a bus-missile or drone as part of a carrier ship in such a future fleet application and would be useful as an artillery piece in NEO. It is likely though that you would eventually need some sort of command and control ship to direct such artillery.

And the Laser will always produce more heat than the power of its beam, regardless of the design, you can't win in thermodynamics.
I have my doubts as to whether you understand how lasers work? That is surely not the case when you have lasers beams that can produce temperatures equivalent to the Sun in a focused area. I really doubt any coolant system known to man would be able to handle that kind of heat if your correct in your assumption, Anonymous. For example a krypton gas laser produces a prodigious amount of heat compared to its beam but a carbon gas laser produces far more heat in its beam than it radiates through its array or lasing medium.



Geoffrey S H said...

I wasn't disagreeing with the idea of robust craft per se, just flummoxed at how to draw such a thing with my limited skills.

Though I did attempt at some reasonably robust looking craft some years ago, but I began to think that the idea of a robust cigar shaped war craft was excessively romantic. A fragile craft craft that can't take even a single hit (but crucially is spindly enough to carry a fair mount of payload) is less romantic and therefore somewhat more likely. You can't armour everything so don't bother armouring anything.

That said, In space you cannot hide. As a result you know where the target is and therefore you have to hit it as quickly and accurately as possible. Bunch up your units and overwhelm the other side enough times and they will aggregate their to face your large numbers. Eventually it may resemble a fleet action more than an artillery duel, even if said fight involves manouvering missiles into position then having them ram the other group. There would still be an attempt to take out the missiles on the way there.

With lasers its less of an artilliery duel (what dug in positions must you somke out? (ignoring asteroids and planet-side positions here for simplicity). Its more like a group of infantrymen in the desert, with no covers seeing an equivalent group and engaging it.

But it really depends on the context. Your attack group may be nothing but intra-system ICBMs or robotic laser platforms... who knows?

Anonymous said...

Cordwainer

The electrical power required produces heat as well. And you will need more electrical power to fire the laser than the power of its beam, since no laser is 100% efficient.

(I^2)*R in this case. or E*I

The heat produced will be the same as the Power in * the Efficiency of the Laser (less than 1)

a 50% efficient 1 GW laser, will need 2GW of Electrical Power, which will produce 2GW of heat.

That is after its generated, there will also be efficiency losses in the generation, and the transmission.

This is the Heat I meant - thus having a big Laser on your ship always produces more heat on your ship than it delivers to the target ship.

Not temperature, heat. The Laser will deliver a much higher temperature of course.

--
NH





Anonymous said...

I doubt we will ever see Space Opera Battles

I think Spacecraft will always be fragile compared to Ocean Warships, because of the relative problems dealing with Mass. I am extrapolating from their current relative fragility.

Except maybe from one direction. I can see an impressive forward shield of some sort.

Since the battles will be much longer range than earth battles, having just a front shield should work.

--
NH

Anonymous said...

Looks like the Laser heat problem is even bigger than I mentioned.

I thought I had remembered something I had read on atomic rockets.

http://www.projectrho.com/public_html/rocket/spacegunconvent.php

Interesting reading.

The Laser as a weapons platform seems to make a huge number of compromises in the name of one huge plus - the speed the laser beam travels.

--
NH

Cordwainer said...

Laser cannons are going to need seriously huge heat radiators. And don't forget that heat radiators really cannot be armored. From http://www.projectrho.com/public_html/rocket/spacegunconvent.php

Except why can't they be armored/ Seems as if the whipple armor front shield you describe could double as a heat radiator if designed correctly.

There are other engineering solutions as well.

The messy alternative is to use open-cycle cooling, where the lasing gas is vented to dispose of the waste heat. Not only does this endanger anything in the path of the exhaust, it limits the number of laser shots to the amount of gas carried.

But Troy Winchester Campbell brings to my attention a recent news item. In 2004, a company named Alfalight, Inc. demonstrated a 970 nm diode laser with a total power conversion efficiency of 65%. They are working in the DARPA Super High Efficiency Diode Sources program. The goal is 80% electrical-to-optical efficiency in the generation of light from stacks of semiconductor diode laser bars, and a power level of 500W/cm2 per diode bar operating continuously.

W = (1.0 / Ce)

where:
•We = Waste power percentage
•Ce = Efficiency of Laser Cannon

Obviously:

CP = BP * We

where:
•CP = Laser Cannon total power (megawatts)
•BP = Beam Power at laser aperture (megawatts)
•We = Waste power percentage

WP = CP - BP

where:
•WP = Waste Power (megawatts)
•CP = Laser Cannon total power (megawatts)
•BP = Beam Power at laser aperture (megawatts)

We can't really know what kind of advances we will see in laser technology in the future. Also, you could have a one use laser or rail gun on a missile to shorten a missiles contact time to kill for instance.

50 MW MJ [oops, energy = megajoules, not power = megawatts] to vaporize 1 kg – roughly the energy of 12 kg of TNT – and has a density of about 2.2 g/cm3. Cutting to the chase, our beam will burn through it at not quite a millimeter per second. Most metals are much less resistant to heat, so the laser will burn through metal hulls way faster). But if you substitute a 5 meter mirror – or a 400 nanometer beam, at the short end of the visible spectrum – you'll burn a smaller hole at half a centimeter per second. Or it will have the same spot size and burn rate at 250 km.

I'm not certain but I think this statement by the owner of this site puts your statement of a 50% efficient 1 GW laser, will need 2GW of Electrical Power, which will produce 2GW of heat, in doubt.

RT = 0.61 * D * L / RL

where:

RT = beam radius at target (m)
D = distance from laser emitter to target (m)
L = wavelength of laser beam (m, see table below)
RL = radius of laser lens or reflector (m)

You are incorrect in that the laser's heat produced will be the same as the Power in * the Efficiency of the Laser (less than 1) due to the effect of diffraction. But, you are correct in that you would also have to deal with the heat required to produce sufficient electrical power for the laser. Fortunately there are chemical lasers that produce there own light source and electrical source to some extent and when combined with gas dynamic effects and efficient laser diodes to complement them they can be quite powerful without requiring on-shore power. A conventional generator the size of semi-truck trailer is sufficient to provide sufficient power via a compulsator. THEL lasers use such a system in the freakin desert for cryin' out loud.

Cordwainer said...

The issue with a laser is that you need a large enough heat sink that can act as armor or as reaction mass. If you use an open cycle method you could direct the gas expelled for propulsion. As for radiators there is no reason why radiators can't either be massive and diffuse enough not to be shot off or sufficiently absorbent that they act as armor. If you are going to have laser ships then your going to need heat-resistant armor so why not make your armor dual use and have it act as a radiator.

As to whether a open cycle laser would be all that more massive that a missile is debatable. It would likely be more mass prohibitive due to the power generation equipment not due to the radiators(which would likely be dual use and somewhat wispy I imagine). The extra amount of coolant carried for a laser would likely be about the same as the fuel payload necessary for a "drone carrier" or "cruise/bus missile" ship so it seems well within the possibility of a sufficiently advanced technology. Near future no doubt missiles and guns will be far more useful than some kind of laser gunship. But as you point out since most battles would be at long range where some kind of spinal mounted laser attached to your forward shield might have potential.

Eth said...

80% and even 65% efficiency laser is quite surprising, particularly for a combat laser; 50% is often considered an optimistic number there. Do you have some resources about it and its (demonstrated and/or planned) capabilities? I'm pretty curious.

The problem, though, is that you have to cope with generation inefficiencies as well. A heat engine (like, say, a nuke electric engine) physically cannot be super-efficient, by which I mean 50% is already pretty optimistic (IIRC, modern nuclear power-plants are 40% efficient). So even if your laser and your generator are extremely efficient, 50% total efficiency is probably a good high-end number.
Which means that for each GJ of laser blasts, you will have to take care of another GJ in waste heat.

Now I agree that attack-resistant radiators may not be as impossible as some would think. Another possibility beyond armouring radiators is using some form of droplet radiator. It may prevent you from manoeuvring much, or it may require magnetic fields to confine the droplets. And there are probably other options as well.

It's also possible that heat sinks will become ridiculously strong.
If you get something much stronger than diamond (or aggregated diamond nanorod) to pressure, you may try to use liquid metallic hydrogen. It requires pressures typically found in Jupiter's core, but once you have it, it will absorb ridiculous amounts of heat when expanding. In addition, with its absurdly high speed of sound, it will give you an Isp of thousands of seconds if released at room temperature.
This is quite theoretical and may actually be impossible, but that's just an example, there may be hugely efficient heat sinks that can be developed in the future, which would alleviate the need for giant radiators during combat.

Then there's indeed open-cycle cooling. I doubt the "burning everything in its path" is a problem, given that nothing should be that close of a warring spacecraft anyway. Using it for propulsion would probably not give you much delta-v, but may be better than wasting it - so you may be on something there.
There's the problem of consumable, well, consumption, but depending on the mission and ship design, that's not necessarily a big problem. If your craft is expected to fire at best five times per engagement (and between resupplies) and you can give it a 30-shot reserve, then you're probably fine. For ships expected to fire many times between resupplies, then you're not.
But the problem has been known for thousands of years, and will exist with missiles/guns/drones anyway.

Geoffrey S H said...

NH, just out of interest, what is your idea of a space engagement?

You said that space opera engagements were unlikely, and I tend to see a space opera engagement as plinking away at extreme "range" with weapons whilst rushing irreversibly towards/ parallel to the enemy force (and for the former, passing them and irreversibly rushing away).

Is it a couple of craft firing the few munitions they can muster, curving them round a gravity well and waiting for the response? I'm curious to hear your opinion on this.

Thucydides said...

While most Western leaders no longer formally take part in combat, many would be leaders have served in the field in the past (or burnish their service reputations). Ever hear of a former presidential candidate named John Kerry? "Bibi" Netanyahu was smoking terrorists when the current president was smoking weed, as the nasty T-shirt says, and England still has a tradition of warrior Kings and Queens (Prince Andrew flew a helicopter with a radar target around the HMS Invincible in order to draw Argentinian anti ship missiles, while his nephew Henry is flying attack helicopters against the Taliban in Afghanistan).

A successful service record may not indicate the ability of a person to carry out tasks as a politician, but it certainly leaves a clear impression of competence in a very unforgiving arena, which may be what voters look for to differentiate candidates from each other.

WRT space war and weapons, it will be easier to "improvise" weapons since the amount of energy being deployed is already so great. While kitty litter is a humorous example (read Atomic Rockets, people), a handful of sand, ball bearings or similar material will cause huge amounts of damage to unshielded systems at orbital or interplanetary velocity. A 20' ISO container full of Lunar dust will weigh several tons, and have more than enough thermal mass to absorb a very high power laser beam; it's impact will cause severe damage or destruction to large shielded systems , ships or space stations. The Rebellion won't need laser armed fighters so long as they have access to space.

Truly militarized systems like lasers make sense where the economy and "infrastructure" and political ecology have grown to the point where it makes sense to have dedicated forces to attack or defend. Lasers have the advantage of being very precise (you can cut through specific pieces of an enemy target; if your sensor resolution is high enough you are shooting at individual pixels on the target screen). In that case, I would suspect that the Laserstar allows the force commander the ability to make a very precise application of force, while his Kineticstars provide the ability to make a pretty wide ranging and serious threat.

Robot weapons are actually being developed in Russia (although the reasoning is not clear; are the Russians thinking to the time when their demographic crash will make it impossible to man the borders and the factory floors, or are they trying to overmatch opponents with tactical firepower right now, an extension of their longstanding view of Artillery as being the "God of War"). Clearly, the sorts of assumptions that constrain Western forces are not at work in Russia, and I suppose the Chinese or Japanese might also see using robotic weapons as an important addition to their arsenal as well.

Geoffrey S H said...

"Truly militarized systems like lasers make sense where the economy and "infrastructure" and political ecology have grown to the point where it makes sense to have dedicated forces to attack or defend."

But will there be an economy in space? Unless you find a way to transport bulk asteroid material to earth without glutting the market then there will be little to do up there.

Certainly there will be little to transport by way of luxury goods, even between earth and mars (the internet and 3d printers will nix that idea, even with the ever present reality of copyright laws).

Anonymous said...

Electricity will most definitely produce every watt of heat as the power involved.

Then add every bit of inefficiency.

Unfortunately our intuitive senses developed on earth where most heat involved in electrical power dissipates into that incredible heat sink, the atmosphere. Add a fan and you can remove huge amounts of waste heat from a system.

You wont get that in Space thus you will have heat nightmares everywhere at these power levels.

Your biggest design helper would be the fact you will delay between firing, because of your charging system. Thus the heat will be spread out a bit over time, much like the charging.

Fire- Cooling/charging - Fire - Cooling/charging - Fire - Cooling/charging and so on.

You could run the radiator's edge on and armor the edges. You could use droplet radiators that are compartmentalized so they will still mostly function as they take damage.

You definitely could keep extra coolant around to run open cycle in a pinch.

And yes Cordwainer I know you have proposed every possible energy storage method in the book so far, but really they all have the same basic problems, Mass and heat.

The best bet for the Laser Battleship will probably be some Ultra capacitor system and super-conductor electrical transmission paths.

I imagine the whole exercise is possible, but I don't think it will be worth it for the majority of a fleet's warships. The Tail (the laser) wags the dog, since Most of the ship only exists in order to fire the Laser.

The Ships without the laser only need tiny radiators by comparison. The save mass everywhere. Heck their performance even goes up with each missile they fire.

--
NH

Anonymous said...

Something Thucydides said about Robots got me thinking. One reason you might want robots is numbers.

Say a future conflict occurs against the Chinese. They can draft a whole lot more soldiers than the US can ..

Geoffrey by Opera I meant any space combat we have seen in any Science Fiction Show or Movie and most games and books. So basically Star Wars, Trek, Babylon 5, BSG, Firefly, Star Gate, Mass Effect, Honorverse - All total Space Opera.

Long range pinking away assuming it is using actual realistic weapons wouldn't fit that description really, I don't think. At least from the logistics side. The setting itself might be Opera to justify why people are fighting in the first place. But at least the idea that space combats don't take place in an area small enough for an air show is subverted.

I think the first actual space combats will be attacks on the satellite infrastructure of the enemy nation, thus hurting their ability to fight on Earth.

So some missions that might be involved.
*Destroying Their Satellites
*Destroying Ships sent to attack your Satellites
*Escorting your Satellite tenders around.


--
NH



Cordwainer said...

Watts and joules are a period of time to watts conversion, but joules to centigrade is roughly 1899 joules to one degree of C, Anonymous. If your measuring of the temperature of the beam to determine the heat produced in the heat sink by the lasing medium then you have plug those numbers into the diffraction/efficiency equation of W = (1.0 / Ce)
that Rick provided and then turn your Watts or joules in W into centigrade.

As to Eth's questions I am only quoting from something that Rick put out on a previous blog, but I am fairly certain they have gotten near 50% efficiency with diode lasers. I would suggest looking into Dr. Y.K. Bae's Photonic Laser Thruster research and Northrop Grumman's FIRESTRIKE solid-state laser modules.

As to Geoffrey's question regarding space opera battles I would take that to mean Star Wars like or Steve White Starfire series like fleet battles with large fleets of specialized vessels capable of operating in close combat in littoral(orbital) environments. In deep space sniping battles make sense but when we get into the littoral ranges then such fleet battles become more likely but also more subject to "emplaced artillery". In other word the type of weapons Anonymous is talking about, essentially disposable drones and planetary based artillery. This means the zone where such "fleet" battles could take place is very limited due to the constraints of not wanting to use too much of your fleet to chase after or confront another fleet in deep space and the obvious defensive advantages that defenders in the above littoral setting would have.

Cordwainer said...

As to whether there will ever be economies in space sufficient for a "real navy" is quite debatable but if people do develop economies in space there will no doubt have need for police forces and a certain level of military forces. I don't see a need anytime soon for big fleet battles. The reason why I think lasers will be more likely to be developed as space weapons is simply because there won't be much need for those crazy battle fleets.

In other words as Thucydides pointe out lasers have the advantage in that they can be very precise and prevent collateral damage and reduce the Kessler problem that kinetic weapons would cause. Most battles are going to occur at a distance and your not going to spend a lot of time chasing the enemy down. So whether you actually need to worry about mass prohibitions of carrying certain weapons is debatable and when you do get into a close combat situation you are going to want to avoid debris scatter, flak and "ricochets".

As to missile ships performance going up with each missile they fire that depends on design and firing mechanism. Yes each launch will increase your rate of acceleration slightly but so would an open cycle laser. Missiles fired from hardpoints or bay gantries that fire forwards of the vessel can vent their gases in such a way that they don't produce a whole lot of pitch and yaw.(but then where do you put that big frontal shield? Hmm.) If you fire from a bay against the ship, firing a missile from a gun or spinning up a missile on a tether will cause some instability in the ships center of mass that has to be accounted for. As for a gentler launch from a catapult or coil gun creates extra heat and mass issues that have to be accounted for as well.

Missiles are not as easy as they sound. The simplest of weapons in a old fashioned artillery gun would be better in terms of stability control over missiles, I think. Obviously small rockets aren't going to cause as much rocking of the boat either. From an efficiency and precision perspective such weapons and perhaps lasers and railguns would make the most sense for a "coast guard in space" application.

Cordwainer said...

Finally, in it is not impossible with materials like carbon nanogel, nanotube, graphene and aerogel to produce a tough kinetic absorbing lightweight shielding material with high thermal conductivity and transmittance along with the ability to conduct and store electricity. Heck you might even include pyro-electric and piezoelectric materials as well to produce useful energy from impacts and thermal energy from lasers and explosives.

Of course such an armor would be expensive with current technology. But who knows it seems likely that such materials technology would develop long before we develop laserstars and torch missiles. Which calls into question whether any of the weapons we have been discussing would be all that effective in the future(either conventional lasers or missiles).

jollyreaper said...

and all of the young smartasses that think they know better.

Well, Tony, you can tell us how the old and crusty asses see it. Being right all the time must be such a glorious burden.

Geoffrey S H said...

"So some missions that might be involved.
*Destroying Their Satellites
*Destroying Ships sent to attack your Satellites
*Escorting your Satellite tenders around."


It would be better to use missiles fired from the equator to do this- little warning time and the ability to select the orbit you want. Once there it would be very difficult to change orbit.

Likewise, you take out enemy anti-satellite missiles with your own anti-missile missiles. Such things require a tech advance or two, but have been considered by the DoD. Or disposable laser platforms fired up on a 3 or 2 stage missile bus?

Actual "ships" in an orbital theatre are unlikely. So I do agree with your on the unlikelihood of opera battles. I just see the term 'ship' as meaning a platform that stays in space and therefore something that would be involved in interplanetary/deep spce combat.

If you want to destroy satellites around mars however, that is where your anti-satellite ships would come in, needing to make the journey from earth. Once there, they would deploy disposable laser platforms to enter the orbit of each satellite, make the kill and then burn up on reentry.

Anonymous said...

Please stop confusing temperature with heat. They are not the same thing. Heat is measured in Watts.

Power is measured in watts. In the Metric system they are analogous. Making it fairly easy to figure out what happens with Electricity.

Consider a laser vs a furnace. The Laser is much much higher temperature. Fire it at a thin piece of steel and it will blow a hole in it. But the rest of the sheet of steel is more or less unaffected.

Throw the whole sheet of steel in the furnace and you can use it to melt the whole sheet of steel at a much lower temperature than the Laser fires.

The furnace has far more heat than the Laser, but much less temperature.

A bit like the Laser Ship and its Target.

--
NH

Anonymous said...

Geoffry, while true it may come to a point where you don't want to wait for a good launch window to do things between LEO and Lunar orbit.

Would be rough if a hurricane in Florida ruins your ability to slow an advance in Pakistan because you cant kill China's Satellites.

Also you may want to be able to replace your satellites at will.

Maybe they live a couple days travel from Earth to help protect them from ground based weapons.

I agree it seems unlikely without some significant "orbital" presence first.

As to the threat of debris - You can clean them up between fights, not really worry about them during.

If we consider LEO and Geo Sync orbit the only Orbits in "Orbital" though, it narrows the window things will happen. Much less volume.

--
NH

Anonymous said...

Also I think its fair to assume the space missile complexity problem is solved if the competing weapons platform is a mult- Megawatt Laser.

Considering the relative maturity of their terrestrial based cousins

--
NH

Cordwainer said...


Heat is actually about the potential in a circuit when talking about direct electrical flow. When discussing the energy required to produce that energy that is usually a product of thermodynamics so it depends on the heat efficiency of your "generator". If its a solar cell this can be very low, if its a steam engine it could be very high. Obviously you could store energy in an ultracapacitor for that portion to store sufficient power for a limited capacity of fire and have a charge up time in between. As for the issue of the laser itself it is the heat from the lasing medium(the furnace) that you have to be concerned with, not the beam. Depending on the lasing medium and how much energy is produced within a period of time will to some extent determine the amount of heat produced on your heat sink. A porous, liquid or plasma state lasing medium has the ability to be more easily dumped or radiated into an heat sink or open space. In other words you can jettison the lasing medium after use or have the medium in a sense open to the "elements" of outer space by forming an unshielded plasma of hot exhaust gases as in some gas dynamic lasers, running a cryogenic fluid across the heat sink and exhausting the resulting hot gases or using a pulsed laser to produce a high temperature beam for a short period of time to produce less heat on the sink or have a diode laser that the light source focused in a beam but light and heat can also radiate out into space via a transparent material(example would be a low energy diode laser inside a high temperature fiber-optic cable). In the last case due to the population inversion most of the photons will still travel in a straight line it is the secondary light wavelengths along with the "heat" that will end up changing the temperature of the sink but if the sink is transparent to that radiation then it conceivably radiate into space more easily.

With a laser the furnace does not have to operate on the same wavelength as the generated beam so just like with a heat engine it has a lot to do with the physical structure of the engine and the type of energy being used to produce useful work that determines the amount of waste heat it produces. A coal furnace is going to possibly produce more heat than a natural gas turbine for the same amount of energy in Watts produced, for instance. Time, heat transmission of the materials used and the efficiency of the design in producing useful energy are all factors in any heat engine even a laser, Anonymous.

Watts is not an analogous measurement because as stated before it does not have a one to one ratio in centigrade, newtons or joules but all of those are essentially one to one because they are metric. Watt is an antiquated English unit for measuring work by horsepower. Heat is not temperature but temperature is the method by which we measure heat and its lack of so I don't quite get what your trying to say their. What is missing from this discussion is the heat transfer coefficient of your lasing medium(the furnace) and the heat sink, which I hinted at before can be different due to the design, materials and lag between the subsets of those systems where heat will build up within the lasers "array".

Eth said...

Cordwainer
Watts is not an analogous measurement because as stated before it does not have a one to one ratio in centigrade, newtons or joules but all of those are essentially one to one because they are metric. Watt is an antiquated English unit for measuring work by horsepower.

Uh, watt is part of the SI unit system, as one Watt is one Joule per second. I'm pretty sure that you confusing with the horsepower unit(s), that I've seen used in car engines and that's pretty much it.
To be truly pedantic, centigrade, on the other end, isn't - it's Kelvin that is :)

About heat, I am pretty sure that you measure heat in Joule, not Watt. Watt would be for heat generation (or dissipation) per second, which is what generators and radiators use (but heat sinks have a capacity in joules in addition to a filling/emptying rate in Watt).
Temperature is indeed not equivalent to heat as it depend on the material, its mass, its state...

NH, I would suggest you to use the Name/URL (URL is optional) when posting instead of the Anonymous option, makes easier to identify your posts.

Thucydides said...

One thing all these arguments about heat overlook is that they assume the "engine" in question is Carnot limited.

I think there will be a great deal of R&D to develop non Carnot limited systems, simply to reduce the amount of mass being carried around. The general design for aneutronic Fusion reactors of any sort involves tapping a beam of high energy ions generated by the reaction for electrical energy, or using the beam as the "engine" of the spacecraft itself. Power conversion could be over 80%, radically reducing the need for coolant, generators, radiators and all the plumbing that goes with Carnot cycle machinery.

Even Dusty Fission Fragment engines can operate as non Carnot limited generators, and the beam of fission particles exiting the reactor at 1% of c can also be tapped as a high quality current source, or as the actual thrust mechanism for the ship.

Anonymous said...

NH says..

1 Watt = 1 joule per second

http://en.wikipedia.org/wiki/Power_%28physics%29

In engineering you typically use watts for heat. In electrical engineering you typically use watts for electrical power (V*I or I^2*R). In a system where you have to design for heat build up in an electric circuit watts = watts. Heat builds up over time, thus it is power.

On earth heat conducts, convects, and radiates away from the source of heat. So if you have a process with lots of waste heat you can give it to the air or water. The radiator of your car is air cooled ultimately. It does almost all cooling through convection not radiation.

In space conduction and convection end at the boundary of your ship. You have to radiate your heat away. Not like a car does. Thus you need a lot more mass. And the radiators have to operate at a much higher temperature.

The power of an engine is also measured in Watts in SI units. Horsepower is actually the "older English" unit. The confusion comes in because James Watt came up with the Horsepower not the Watt, the SI Power unit Watt was later named in honor of Mr Watt.

Since engine power goes up based on Engine rate of spin, horsepower is up near its peak rpm. Torque would be the energy component. Waste heat created based on the power used as you move your car around. If your car was in space, and you fed the engine oxygen to make it run It would overheat quickly, bad stuff would happen and the system would fail.

Temperature really is distinct, its like the Joule. You obviously can't heat your house with a lit cigarette, it has high enough temperature but there is not enough heat there. So you use a bigger fire, one that is lower temperature than the cigarette. And takes time.

Temperature transfer over time is what gives you heat. Energy over time gives you Watts. Same thing really. I realize most people never use this stuff after college physics, but its really pretty basic stuff, sorry for the confusion.

So in our discussion; My Missile Boat has heat problems basically equivalent to what was faced by Apollo or Skylab or Mir or the Space Shuttle. Its already been done.

The Laser Battleship has heat problems on a scale NO ONE HAS EVER dealt with using only radiation cooling yet.

Not that it cant be done, they have ideas about how to do all of it and have tested the systems involved. But it is involved. And you really would need a reason to need the Laser to go through all that mess.

Simply shooting at other spacecraft isn't necessarily it. Not unless the advantage of the Laser beam's speed becomes an distinct advantage in a fight. Which might be a range of engagement type problem. Which then suggests your Laser better be pretty accurate at a distance to outclass the missiles.

--
NH

NH said...

Thucydides, I think a lot of these problems will exist regardless. Especially with high power weapons systems. Just transferring the electricity will be a problem we don't worry about on Earth.

On Earth the electrical wire heats up and convects the heat away. In space it heats up, and keeps heating up unless you do something to cool it off.

I think superconductors will abound in any of these high energy weapons designs. Which will bring their own engineering problems, since superconductors don't work when heated up ..


Cordwainer,
Solar panels are not actually low heat. They absorb a lot more solar radiation than they convert into electricity. Thus using Solar panels will also "produce" a lot of heat you will need to deal with on the spacecraft.

A square meter of panel will be subjected to about 1300 watts of Solar radiation. A very good solar panel will turn that into about 530 watts of electricity. The rest of the illumination? Most of it heats up the panel. The hotter the panel gets, the less efficient it becomes. On earth the Panel convects it away.


Eth,
Thanks

--
NH

Cordwainer said...

What Eth said. Yes, the Watt is has been doctored into SI as part of Carnot's work with steampower, because at the time they were still utilizing the caloric theory of heat and had not fully moved over to the mechanical theory of heat. Which is why joules and watts are often used interchangeably but you really do need to look at the measured differences in temperature by units in Kelvin or centigrade in relation to joules and watts at some point when designing an cooling system because you need to know how fast heat transfers and dissipates within that system not just how fast the heat gains as a result of work.

I think I said or implied that solar panels are just more efficient at radiating heat and don't require you to directly create heat to produce energy, NH. Not that they are necessarily low heat. Also, from a practical angle it seems that plenty of satellites utilize photovoltaics panels just fine without incident. Also, some photovoltaics actually work better when they heat up and there is even a form of solar panel that gains energy from heat called a thermo-photovoltaic panel. I think your starting to pick at straws here NH.

Space is a vacuum, and heat can only be exchanged through radiation. However, that is a quite powerful means of exchanging heat. Have you ever stood in front of a campfire on a very cold winter night? While facing the fire you may feel roasted in your face, while your back feels frigid. The fire radiates heat at you, and your back radiates heat into the cold night. Of course, the cold air around you plays a role, but if there is no wind, the major heat exchange is radiation. In space this is turned to the extreme. Without any star or planet nearby the temperature of space (as defined by radiation) is 3 K (-270 centigrade), the temperature of the ubiquitous background radiation from the Big Bang, i.e. extremely cold indeed. A spacecraft is roasted on the side that faces the sun and very effectively cooled on the opposite side. Objects in space (that is, in the absence of air) are heated by radiation on their Sun-facing side and then, because there is nothing (like air, which acts as a "blanket") to reflect and reradiate the heat back toward the side facing away from the Sun, most of that heat escapes into space. This also happens to the Earth, which is heated by the Sun during the day and radiates some of that heat back into space during the night. However, the atmosphere acts like a blanket and keeps much of the heat from escaping during the night. http://helios.gsfc.nasa.gov/qa_sp_ht.html

I agree lasers would probably not be very good anti-ship weapons for purposes of warfare but for point defense against guided missiles in a space environment where there is little physical cover and attacks will most likely have to travel vast distances then lasers work out fine. Due to mass issues and Kessler problems I doubt missiles will be extremely large, they will probably be no bigger than ICBMS. I am not saying that lasers will be preferred over other weapons, just that they have some valid applications.

NH said...

I am sorry but you are really not getting the basics of heat and power.

The Watt isn't doctored into anything. It is the SI unit for Power. Plain and simple. Heat is power. Temperature is Energy.

http://en.wikipedia.org/wiki/Watt

The Solar Panels are heated by the Sun, just like any dark object would be. The problem is the heat from the Sun exceeds the amount of electrical power they produce. Thus you basically have the equivalent of waste heat. On earth that is no big deal since you can convect, conduct and radiate the heat away.

In space you can only radiate it away making the panel run hotter. Making it less effective. This is due to the way semi-conductors operate. Current goes up, Voltage goes down, overall produced power goes down.

Your fire example really isn't the whole story. The fire is also transferring heat through convection. The air "behind" the observer is cooler than the air in front of the observer since that air is closer to the fire.

If convection were inferior to radiation as a means of heat transfer there would be no such thing as a cooling fan.

Instead convection is much more useful in most cases. Which explains things like car radiators (which uses convection), Cooling Towers, The fans in your computer case ..

It would be more useful in Space too, but someone forgot to put the air up there.

Of course if there were air in space, the convection from the Sun would have melted everything up to several AU out, consider that the sun lights the earth at a "standard" of 1000 watts/meter through only radiation.

Thucydides said...

Of course a non Carnot mechanism still generates waste heat, my point is that this becomes a smaller part of the problem since not only is the efficiency increased, but a lot of the mass associated with Carnot "engines" is also eliminated.

An aneutronic fusion reactor does not "need" wiring, for example, since the fusion energy is being released as a stream of charged ions; by definition this is high quality electrical current, all you need to do is find a way to complete the circuit. A laser weapon might be energized by shunting the beam into the lasing medium, and I am sure you can think of other direct conversion tricks.

The radiators and heat sinks will be far smaller with these sorts of systems, which has multiple knock off effects as well (less mass to move around means you don't need as much engine power, which means you can have a smaller engine producing less heat etc.)

If these sorts of systems can be developed, there will also be lots of positive effects here on Earth as well. The large areas devoted to cooling in current Earthly power plants can be dramatically shrunken, cooling water consumption will be reduced and generators can be built close to the customers, reducing the costs of transmissions systems (towers, wires, transformers etc.)

NH said...

Thermo-Solar uses the heat to do work. Stuff like preheating a water heater and so forth. There is value to the heat provided.

However the heat always reduces the photo-voltaic effect. It also makes all the resistances in the panel go up. This is just how the materials that make these things up behave.

I am not picking at straws I am trying to convey all this stuff is harder to do in space than on earth. Space is the ultimate difficult environment to solve engineering challenges in.

Your Laser in the Desert example you used earlier. The Desert is far easier place to build a working high power laser than space.

Space Engineering is hard, really hard. Most science fiction authors decide to give up on hard Science fiction as they begin to grasp that. Even most "hard" science fiction is a lot softer than reality.

NH said...

Thucydides

Hmm. Since you already would have a handy supply of electrons, could you then accelerate them and have a particle beam weapon?

You already would have had to solve the massive electric-magnetic challenges to make the fusion work in the first place

This stuff is kind of far future compared to some of the other stuff we have been talking about, but it sure would make things simpler.

Make it fire "backwards" and you have a auxiliary thrust booster and particle beam combined. Basically a way to increase the range of Jon's law.

Thucydides said...

If any of the various aneutronic fusion schemes work, then you will have a stream of charged particles coming out of the device as your power output. If you can keep the beam focused, then by definition you also have a particle beam weapon or generator.

On a more practical note, if you eject the beam through a magnetic nozzle, then you have a fusion engine with an ISP of about 1,000,000 seconds.

As for how far away any of this is, I will note that most of these devices have demonstrated similar results of plasma temperature and confinement to more "conventional" setups using only a fraction of the time and money. This is no garuntee that any of these will work, but is suggestive.

For a high efficiency non Carnot system that will work, look no farther than dusty fragment fission reactors. Once you reach criticality, the ejected fragments will be emerging from the reactor at @ 1% c, with all the useful things that implies.

Thucydides said...

Things are getting quiet, so I thought I'd throw out an interesting idea about using the voids in asteroids as colony spaces.

The blog http://gravitationalballoon.blogspot.com.au has lots of interesting ideas and worked examples. The idea of a 3D space housing millions or even billions of people as a mature social and political structure has interesting implications (as a city state, it would have the sort of economic muscle of continental nations on Earth).

Enjoy

NH said...

Interesting.

I wonder if you would actually, necessarily, even need the asteroid. Once you blew up a cylinder balloon, you could coat it with different polymer and foil layers to act as shielding.

I expect the Balloon idea is in preference to say a Lunar colony due to the gravity problem.

Thucydides said...

I imagine the asteroid is needed as the source of the raw materials to build the thing.

Otherwise, as you suggest, it would be sufficient to blow up the bubble and fill the space with the rotating structures.

If the supposition that the asteroids are full of voids of various sizes, then it also makes a space colony more like a modern city; there may be an urban "core" where the biggest bubble is located, and multiple "suburbs" with bubbles of various sizes. Different "neighbourhoods" could ask exist, everything from "bohemian" neighbourhoods with artists (or waiters with artistic pretensions), "Chinatowns" and industrial parks.

The way people and societies will evolve is perhaps the most fascinating thing about Science Fiction and futurology.

NH said...

I expect you would want to make the Balloon out of a polymer of some kind which probably means oil, which isn't likely to be on any Near Earth Asteroids.

The Asteroid outer portion works as shielding that you don't have to lift to orbit of course. But you have to lift most everything else anyway .. so the shield may or may not be much more prohibitive depending on its mass.

The asteroid-less version has the advantage that it could be closer to earth.

If you remove the spin gravity idea, the same sort of balloon environment could probably be modified to work on the Moon on a smaller scale.

Or on a much smaller scale, the habitat of a spacecraft could always be a Balloon cylinder, spin or no spin.

Geoffrey S H said...

If the interior is big enough, might you have nations states developing instead of city states? A central 'life support council' might be independent of certain other civic bodies. An administrative plurality might thus emerge.

Thucydides said...

Since many asteroids have carbon and hydrogen in large amounts, and you are in an environment with access to large amounts of energy (solar radiation), then you can simply make the polymers out of the raw materials at hand.

Even if you are in a resource poor environment, you could probably render the asteroidal material down to metals and make a balloon out of aluminum foil. or perhaps silicon if you are in a metal poor environment.

I think the ultimate end that the author has in mind is independent nation states with up to a billion people in a compact 3D environment, which would have some very interesting, if hard to predict consequences. A nation as populous as China or India packed in a volume of a few hundred cubic kilometres would be much different from anything we have ever experienced on Earth, and how they are structured socially or run in terms of government would be quite alien to us.

NH said...

Perhaps, but carting the solar panels and machinery up there to do so might be harder than simply manufacturing the materials on earth and lifting the finished products.

Maybe the idea of the self sustaining expansion can use the materials.

On that related note,a nuclear reactor is probably more mass efficient in terms of energy per payload kg than Solar panels.



NH said...

As to the massive population and related challenges in closer quarters, that one will already play out on Earth in the next few centuries.

We are on course towards reducing possible livable regions while simultaneously increasing the population and reducing probable agricultural output.

Some of the technological and cultural adaptations made to deal with those problems will probably be directly applicable to space expansion, if humanity decides to go that route.

Eth said...

The 'three generations rule' comes to mind about those colonies. And if something goes really wrong, then evacuation may not be an option for a billion-strong balloon - particularly if it is linked to a system-wide recession or other wide-scale problem.

That said, I feel like a three generations rule in a softer form may also exist for large Earth-side cities. As it becomes vast enough, a city could see mass starvations or droughts if for some reason the varied networks feeding it were perturbed. In some cases you could even see mass asphyxiation if power for air circulation for, say, underground buildings went down.

Geoffrey S H said...

Before we even think about long-term space structures, we need a way to create environments in 'relatively' enclosed spaces that can perpetuate without any human intervention or maintenance for millenia. That applies to large scale space stations and asteroid colonies.

Ironically that would favour colonies so large they can have their own internal weather and eco-system that can maintain itself.

Thucydides said...

The combined areas of gravity balloon colonies built into a large asteroid would probably be large enough to sustain a stable ecosystem (actually multiple ecosystems, since the volume would be split between multiple gravity balloons). Only early generation balloons would not have viable ecosystems, simply because the balloons would be too small, and the science of creating viable ecosystems isn't developed enough to do so at this point in time.

I have argued in the past that one of the things the space environment allows us to do is simplify things. Why cart up or try to build solar panels when you can whip up a mirror out of metallic foil and focus sunlight to whatever degree you desire? A broad focus would bath an aperture into the gravity balloon with light, while a tight focus would literally flash asteroidal rock into vapour or plasma for industrial processing (pass the plasma through a powerful magnet and different elements can be "bent" out of the stream and condensed on cold plates).

Reading some of the "in depth" posts on the gravity balloon idea shows the author has similar ideas; for example thermal control would be through allowing air to flow through the rotating structures in a controlled one way path, and "public transit" would take advantage of these air streams to gently "flow" people along between habs (although he is less clear on how you get back to the starting point....). The space environment is very different from what we are used to, so problems will have much different solutions as well.

Geoffrey S Hicking said...

And for life support you could coat the hull with this :)

https://vimeo.com/101734446

Cordwainer said...

Watt is a measurement of work not power(power is the energy to do the work, not the measurement if we want to be semantically split hairs, NH). The unit is defined as joule per second[1] and can be used to express the rate of energy conversion or transfer with respect to time. The terms power and energy are frequently confused. Power is the rate at which energy is generated or consumed and hence is measured in units (e.g. watts) that represent 'energy per unit time'.For example, when a light bulb with a power rating of 100W is turned on for one hour, the energy used is 100 watt hours (W·h), 0.1 kilowatt hour, or 360 kJ. This same amount of energy would light a 40-watt bulb for 2.5 hours, or a 50-watt bulb for 2 hours. A power station would be rated in multiples of watts, but its annual energy sales would be in multiples of watt hours. A kilowatt hour is the amount of energy equivalent to a steady power of 1 kilowatt running for 1 hour, or 3.6 MJ (1000 watts × 3600 seconds (i.e., 60 seconds per minute × 60 minutes per hour) = 3,600,000 joules = 3.6 MJ).

Terms such as watts per hour are often misused when watts would be correct.[20] Watts per hour properly refers to the change of power per hour. Watts per hour (W/h) might be useful to characterize the ramp-up behavior of power plants. For example, a power plant that reaches a power output of 1 MW from 0 MW in 15 minutes has a ramp-up rate of 4 MW/h. Hydroelectric power plants have a very high ramp-up rate, which makes them particularly useful in peak load and emergency situations.
So basically what I was saying and you seem to be confusing NH is that your using watt without reference to time or how it related in actual measurement of joules, because it is not 1 to 1 because of the relation of energy conversion in respect to time. Also not all energy is thermal energy or produces the same rate of waste heat when utilized. Energy can be stored in many forms and mediums and how it is stored and released determines the rate of thermal energy produced as waste heat due to mechanical friction or radiation. The joule measures mechanical work not how that mechanical work is accomplished. For instance the joule can be define as either the work required to move an electric charge of one coulomb through an electrical potential difference of one volt, or one '"coulomb volt" (C·V). The work required to move an electric charge of one coulomb through an electrical potential difference of one volt, or one '"coulomb volt" (C·V) or
the work required to produce one watt of power for one second, or one "watt second" (W·s) (compare kilowatt hour - 3.6 megajoules). This relationship can be used to define the watt. So one kilowatt of laser power is not one kilojoule of power because:
1. The watt never stands alone it is always defined by a time period.
2. The joules in waste heat that has to be dumped is not always the same as the amount of watts in work due to the fact that you can have conversion from one medium of energy to another which does not produce the same amount of heat as power from a thermal medium(example the difference in waste heat from a combustion motor and an electrical motor measured in the same watts of output will not have the same value). A laser is not a blowtorch that's a bad analogy and you know it NH you just don't want to admit it.





Cordwainer said...

The issue with a laser is not really the heat of the lasing medium since this medium can actually be held outside of your space craft as a plasma or exhaust stream as in the case of some gas dynamic lasers, the medium can also be disposable allowing you to shunt heat rapidly. An explosive gas dynamic laser on a missile would have the effect of not dumping heat on your spaceship while also increasing the missiles kill zone and shortening time to intercept for instance.

The real problem with laser weapons in space is the heat from the electrical energy needed to power the damn thing as you pointed out NH even with solid-state or non-Carnot power generation technology you would need large radiators with a high capacity for heat absorption and heat dissipation.

I imagine this would be no different for a particle weapon using aneutronic fusion or other "radiant" heat engines(versus chemical or electrical storage mediums of energy)Sticking a fusion drive on a ship has even more engineering issues to be solved than a fission reactor or even a laser I would think(unless dealing with a pulsed set up like MSNWR or PuFF, in which case you wouldn't be able to turn it into a particle beam weapon). This does make me wonder why Thucydides gets an engineering pass and I don't NH, sound like you just don't like me. Aww, my feelings are hurt. Also, a particle beam(and to some extent a fusion drive) is going to require some fancy engineering to keep charged particles and electrical charge from building up on your ship and would have the unfortunate or fortunate effect of certain death from electrocution due to such charge build up for any ship struck by a charged particle beam weapon. Any society that adopts such an unethical weapon would need to have some really good de-gaussing technology, Faraday cages, paraffin wax and radiation shielding might save the crew after the initial strike by such a weapon but as soon as you land or dock your ship your crew and ship are going to get fried by the difference in electrical potential.

Solar cells have pretty good thermal efficiency and do actually increase in their efficiency when they reach a certain optimal temperature depending upon the cell. They also have the advantage of being light weight, flat and conformable with high surface area, all of which helps when designing heat radiator and coolant systems. As for a very large mirror is that mirrors often have to be constructed from solid materials while solar cells can be produced from lighter more porous materials. The mirror also has to keep its shape to direct light on an object and the larger the mirror the more support material you will need. Large solar cell collector panels could be made conformable and use the asteroid for support and the asteroid rock itself would offer better protection from radiation for a habitat than a gravity balloon. I have my doubts as to whether a balloon habitat becomes feasible at very large sizes, at some point it requires struts and supports to maintain it's shape(at least if you want to spin it for artificial gravity).

What you need for a space economy of scale is not permanent self sustaining habitats in space, all you need is semi-permanent habitats that provide sufficient economic worth to those planet-side. NEO colonies for mining the Moon or NEO bodies wouldn't need to be fully self-sustaining just mostly self-sustaining.

NH said...

There was no pass I commented that the fusion would have been a much farther future idea, you perhaps missed it.
---

You are losing me at "Watt is a measurement of work not power" Watt measures power, period.

Power is also not "the energy to do work" it is the Rate work is done.

This is why in an engine power is based on engine revolutions. In an Electric circuit its Volts*Amps (Energy*Current)

You are going to turn the laser on for some measurable amount of time. The Energy in Joules*On Time will equal the Laser's Power. The Efficiency of the Laser will determine how much Power In you will need to get that Power Out.

The Power In vs Power Out is Power you have to deal with on your spacecraft as heat. Since your ship wont be plugged into the wall you will also be making the Power In on the ship. The Nuclear Reactor and the Generating system and moving it to the Storage system then moving it to the Laser. All of that power will also mean waste heat. As suggested the best generating system is likely to be 40% efficient.

So basically lets say you have a Laser that fires 10 joules for .1 second. The Laser is 50% efficient. Your Laser Beam is 1 Watt (10*0.1) Your Power In is 20 joules for 0.1 second, so 2 watts. You thus need 2 watts from your capacitors. Your reactor is 40% efficient so you originally needed 5 watts to charge them.

If you have electrical line losses you will need to account for those. Line losses are based on current and the transmission media. The higher current the more mass you will need for transmission. Line losses will be lost as heat.

So when you get into the millions of watts this gets to be real numbers.

Please note you can charge a capacitor slowly and discharge quickly, Watts In and Watts out will be about the same. That is because Watt is not a measurement of time. It has to be this way or your system will never work.

Same for the heat problem. You will need to make your heat over a length of time so that your radiator system can actually deal with the heat.

So the Laser will have a cycle like .. Charge Capacitors / Heat up coolant / Radiate Heat --> Fire Laser--> Charge Capacitors / heat up coolant / Radiate Heat. Your cooling system has to be able to handle this or eventually there will be too much heat in the system.

You can design around all this, but it takes MASS.

Mass the Missile ship doesn't need because it doesn't need any of those systems. It doesn't have a laser nor the electrical power requirement.

It's big mass problem is the propulsion system and how many missiles it carries. Stuff we can solve today.

Or to put it another way. The Laser Ship depends on technologies we haven't completely developed yet. The Missile Ship could be built using 1960's tech.

NH said...

As to the Solar Panels.

Photo Voltaic are semi-conductors. A semi-conductor becomes more conductive the hotter it gets.

Sounds great right? The hotter a panel gets the more current it produces. YAY!

However in a Solar panel, the difference in potential between the sides of the PN junctions also goes down as the Semi-conductor gets hotter. So the hotter a panel gets, the less Voltage (energy) it produces. BOO!

Since Power equals Current * Voltage, this means you would want effect 1 to happen faster than effect 2.

Unfortunately the exact opposite happens and Power always goes down with temperature, sorry.

The Panel will always run hotter in space than on earth in the same light due to the removal of convection cooling.

Thus it will be relatively less efficient in space for the same illumination. One reason they always try for the most efficient panels they can use in space missions.

While the effect isn't truly linear its treated as if it is for temperatures you will typically see (on Earth anyway) If you dig deep into a Solar Manufacturer's specifications you will see that the listed power are for 1000 Watts/meter illumination at 25C. There will be coefficients listed for the increase in current and losses in Voltage and Power.

Its important to remember that the illumination in space can be higher than on earth and thus the panel can have power gains, but those will also be offset by increased panel temperature due to higher sun load.

The illumination gains/loses aren't truly linear either but generally from 800-1200 w/m they are treated as such, often 600-1500 are lumped in for simplicities sake.

Really though on a mass basis the Nuclear Reactor is probably a better bet. The idea you will use Solar panels to avoid the heat produced by the nuclear reactor seems self defeating.

Since really the heat problem is a mass problem. And nuclear power is probably the most efficient KW/KG source likely to be available.

The problem comes in when you want Megawatts of power on a Spacecraft. Then you have all the problems that Megawatts of power entail.

Cordwainer said...

See now your actually making sense NH. Your quantifying that its a relationship of power out versus power in instead of stating the power in watts is always equal to waste heat in joules which is what the argument was originally about because you implied that watts in power is equal to "waste" heat in joules which is not always the case. You just said it better than I did with the statemtent, "Power is also not "the energy to do work" it is the Rate work is done. Which is what I was trying to express. The joules in heat produced is dependent upon the amount of time something is "on" and the rate of power out versus power in as well as the medium by which that power is generated.

I agree with you that missiles technology is obviously easier to produce with current technology while a laser ship would be more difficult, that's a no brainer. The point I was making that it wouldn't be that hard to make a laser ship and in fact the thermal issue might be easier to solve than the thermal issues related to a nuclear reactor in space for reasons I will get into later. Also, laser weapons in space would offer some definite advantages over missiles and projectile weapons in terms of precise targeting, avoiding collateral damage and the Kessler effect.

Cordwainer said...

You don't need a megawatt death ray for an effective laser weapon just a couple or few hundred kilowatts would suffice to make an effective weapon for point defense and delivering minor ship to ship damage. Unlike a NTR or a fusion rocket a lasers array and its most of the systems related to the laser where heat would be a real issue would or could be mounted on the periphery of the ships hull. While power generation systems for the laser might be more internal and you would have to deal with the running of electrical lines or beamed energy resonance coils to charge your capacitors those capacitors and the power generation equipment could be spread over a large area.

On the other hand a propulsion system really is a blow torch attached to the innards of ones ship to some degree(of course you can design the ship to have a porous open structure of beams and divide your crew habitat from your propulsion system and or reactor).
This is the reason why rockets are usually designed to be expendable and orbital maneuver engines typically have a maximum burn time before they reach an unsafe threshold. The waste heat issue for charging a laser up is well within technological limits, line losses and heat from power generation can be solved and the laser doesn't have to us capacitors which would have heat issue themselves. You can use flywheels or compulsators for instance. It is the discharge heat that is an issue but that to can be dealt with to some extent by using a gas-dynamic chemical laser medium combined with solid-state illumination sources like in an ElectricOIL laser. This would lower the amount of heat from direct electrical injection sources and allow for some adiabatic cooling of the lasers optical cavity. You could technically have a population inversion occur in an exhaust stream external to outer space although you would want some kind of focal array or lensing system in front to effectively aim and focus the lasers beam, but maybe you could control the exhaust stream or plasma itself to allow some fine control of the beam somehow.

Cordwainer said...

While the PN junction is limited by the materials used and the design of the junction to some extent that does not mean that solar cells could feasibly be improved or changes the fact that compared to many other power generation devices they don't generate a lot of waste heat and by their nature offer a large surface area for radiating waste heat(as well as absorbing heat unfortunately). Heat gain from higher sun load is an issue but there are adaptable cells that would reduce or reflect some of that heat gain and cooling a flat panel of solar cells in the megawatt/kilowatt range would be easier than cooling a nuclear reactor of the same power. I admit lots of Stirling RTG's or MITEE style generators placed some distance apart from one another would probably be more energy efficient, less mass prohibitive and have the advantage of being used as a hybrid propulsion/power generation system if we are talking about a space vehicle application like warship. I don't know whether they would be better or worse in terms of "waste heat" issues over photovoltaics but what is certain is that solar panels could be held external to the vehicle with less supporting mass. Also, a lot of the coolant needs for a nuclear reactor would be liquid, molten or cryogenic in nature while solar panels could be cooled use more solid or particulate radiators and would have better surface area to utilize both direct radiation into space and liquid/cryogenic cooling the panels. Also, the whole mass argument is somewhat complicate since it is actually the weight of the items you would have to lug up out a gravity well or between gravity wells that is important, so the lighter weight the materials the better. Solar cells might not be as efficient as a nuclear reactor but the weight of carrying all the things associated with a nuclear reactor are. For example coolant, nuclear fuel, radiation shielding and the support girders for attaching it to your ship would mostly have to brought up from Earth or manufactured in space and not all of those materials are light weight or easy to come by in space. A solar cell can easily be manufacture from in-situ resources in space and would require a far smaller inventory of resources or materials to build, which means fewer dedicated industries to building them.

Cordwainer said...

While watts can be used to express the potential load of energy something has IRL it is always going to be effected by the dynamics of time and thermodynamic equilibrium. There is no such thing as a closed system. Even capacitors don't hold there charge forever and a rubber band will eventually decay and lose its elasticity.

To think that scientific measurements have a permanency or exact precision is foolhardy they have a probabilistic range or tenancy. Engineers use ideal formulas when designing things for the real world which I have always thought was bit looney to expect the real world to conform with a "mostly good" mathematical representation of the world. It works fine in most cases but I think it creates for inflexible thinking in relation to how something actually behaves in the real world, particularly when it comes down to demonstrative testing of a design in extreme environments.

Cordwainer said...

Hmm. So how do you steer a guided missile in space. No air so fins won't work and a gimbaled thruster would have to put up with the issue of heat build-up over time so your maximum burn time would be limited. I suppose you could have solid rocket boosters in segments with maneuvering rockets in the nose or out on pylons. Once it gets up to a certain speed it could coast to its target, but you would probably need some sort of secondary propulsion system for matching trajectories and speed with its target in case they try evasive maneuvers. So a liquid fueled pylon mounted system would seem to be more likely than nose-mounted retro-rockets since a pylon mounted system could be used for maneuver and acceleration.

Space is vast and radio or laser guidance would allow for the enemy to home in on the attacking ship. While you can't hid in space you probably wouldn't want to leave a trail of bread crumbs all the way back to your ship. So your missile will need to be self-guided.

Space is vast so lots of time to get out of the way or intercept the incoming missile unless you are at spitting distance. So your missile may need to be armed, armored or just plain massive like a bus-missile. Also, if you want to hit anything at more than spitting distance your missile will need to have a lot of fuel or you will need to overwhelm your opponent with enough missiles to create an area denial or carpet bomb effect. You can use gravitational effects to and the micro-gravity environment to get some decent acceleration going though so the time to kill might be pretty short at moderate distances.

Space is vast so the time to kill for a homing missile may be long and since space is a vacuum it will make more sense to use a kinetic warhead of some type(shaped charge, casaba howitzer) than a purely explosive one. Multiple warheads or missiles on a missile with a shotgun spread would be most effective.

A guided missile is space looks more and more like an automated drone to me.

NH said...

I spent well over an hour typing up responses but evidently the system ate them and I didn't save my work.

Suffice it to say, Cordwainer I haven't actually changed what I have said at all. In fact, I feel my posts have been much too repetitive on those topics, and I am probably boring everyone. Indeed I feel that I have already addressed most of your comments/questions in this thread already.

So instead of typing it all again, Ill refer you to the Atomic Rockets website which discusses Space Missiles, Lasers, Nuclear Reactors, Thermal Propulsion Systems, Dealing with Heat and all this in detail.

(If my other post miraculously reappears I apologize if that one bores anyone)

Geoffrey S H said...

Potential new idea for people to discuss:

I have been working on a setting that has similarities (superficially) to the medieval period. Various warring powers with holdings on planets that don't always obey the central executive on the homeworld (essentially pre-absolutism europe/asia in space). I found myself inserting occasional groups of raiders under a nominal leadership that were sufficiently far from the inhabited worlds in each system that it was extremely difficult to reach them without a large supply train. Due to some fancy meditation powers and extreme ration discipline these raiders make that distance with relative 'ease' (though only a few of the total population at their bases have this power) and could take merchant craft from those civilized areas but usually settled with raiding the lawless areas nearer their asteroid settlements. When craft are sent to intercept approaching raiders they usually split up to tackle individual merchant craft (which have to engage in trade for a livelihood and so take the occasional risk of raiding in their stride), with the raiders that are targeted by escort craft then bugging out. So essentially both sides can give and take losses without the need for handwavium stealth systems

The larger powers occasionally organize large expeditions to clean out these fortresses but are often deterred by the potentially massive defensive forces arrayed against them, consisting of ramshackle craft that can be cheap to make. They could smash them but it would take effort better spent protecting core worlds from larger more threatening powers.
Making the crossing with a supply train is extremely expensive and replicating the ramshackle craft that have the mass ratio sufficient to allow raiders to journey back and forth is considered an unacceptable risk to expensive military crews.

Essentially these 'pirates' are Donbass raiders in space. Not hidden but far away.

Technology is essentially 1950s rocketpunk (or even earlier if I can manage it), with the raiders in an asteroid orbiting around Mars's distance from the sun, and the civilized powers on a planet with earth's orbit. Liquid fuel rockets and guided shell systems are predominant and trade with other star systems is accomplished by a precursor stargate 1/4 of the way between the civilized powers and the raiders.

Totally ludicrous or a reasonably plot hole free way of putting in 'pirates'? Feel free to tear apart.

Thucydides said...

Lots of interesting tangents in the conversation. I am starting to think that Rick simply doesn't need to post anything; just a new page once a months and having only one word: Comments!

WRT solar PV vs mirrors. while PV isn't a Carnot system it is (as noted) still limited by issues of temperature, and most particularly the differential between the "hot" side and the "cold" side. Some systems on Earth are starting to use a water cooled "cold" side in order to overcome the limits of temperature, and something like that could be used in a space setting. Since we want to limit mass in space, heat pipes are probably the appropriate means of cooling a PV array.

Mirrors in space might not need extensive structural support to maintain focus, a spinning mirror will maintain its shape and orientation in free fall, and a small tension structure might suffice for fine control rather than a large compression structure.

The Gravity Balloon idea separates the pressure bubble from the gravity structure. Think of a large balloon with a series of threads strung from side to side inside the balloon, then have a series of beads on the threads, these represent the spinning gravity structures.

Long range missile weapons won't have much difficulty finding targets in space, since any target system will shine brightly in the Infrared band of the spectrum. I think that metamaterial shells around the target might have *some* ability to moderate this, but mostly by reducing the range where a seeker can effectively identify the target. The missile's profile might be a fast boost, long coast to the target zone and then a final burn to zero in to the target. The old AIM-54 Phoenix is a loose analogy, the missile shot up into the stratosphere under rocket power and essentially glided towards the target; diving down to do the actual intercept of the (very surprised) target.

OTOH, in many discussion boards (and indeed right here in Rocketpunk; look at the various posts in the Space War series), it seems the best way to use laser weapons is to build them as large as possible and strike targets as far away as possible. Looking at the sorts of calculations on how to disable an enemy laser on the various boards, the general rule is that you need to rapidly ramp up the number of kinetic energy weapons (almost exponentially) as the power of the enemy laser increases. Against the Ravening Beam of Death Xaser capable of shooting targets at a distance of a light second, you need hundreds of thousands of Soda Cans of Death to ensure that some will get through the beam and strike the laser star. http://www.rocketpunk-manifesto.com/2009/09/further-battles-of-spherical-war-cows.html
See http://francisdrakex.deviantart.com/art/The-Soda-Can-of-Death-424421427 as well.

Given the size of RBOD's (kilometre sized electron beam injectors for a FEL weapon), having mounting points for missile batteries (busses carrying SCoD's) seems to be a relatively straightforward fix, separate laserstars and kineticstars might not even exist. We will have huge weapons carriers in the constellation with smaller manned "cutters" to supply command and control and carry out the missions which do not require the big guns (inspections, diplomacy, "showing the flag", etc.)

NH said...

Okay - so on reflecting. I will approach this from hopefully different angles.

-------
The Nuclear reactor is still more effective than any of those Electrical Power creation schemes on a Mass basis. You can't magic Solar Panels or any of those other concepts to be more effective. It is an energy problem.

The Nuclear reactor is working on E=MC^2, it is orders of magnitude more effective than any of those other systems. It has more energy available than you can intuitively imagine. It just requires mass to be able to utilize it. It will still be less mass per watt than any Solar of any technology real or imagined. And Solar is probably the most effective of competing systems for long term power. Think of it this way-- Solar power is nuclear power that starts at the sun and is radiated into Space. Then you try to use some tiny bit of it you convert with a semi-conductor from 90 million miles away.

The other systems are for when you don't need/want the kind of power a nuclear reactor will provide. Or when Mass is not a design consideration. On a combat spacecraft I find it impossible to believe mass will not be a design consideration.

Most likely the first space reactors are likely to be fission reactors. Fusion having a lot more technical challenges. Anti-matter having both technical and logistical problems. We use fission all the time. Our reactors are typically a lot less impressive than the could be. Mainly due to political concerns and technical challenges. And yet even these basic reactors at really low levels of enrichment can make Submarines with Megawatt scale electrical power than can run for decades without refueling.

If Space were an Ocean, a Fission reactor is all you would need to make a heavily armored Laser Star a reality. The water gives you incredible cooling potential and you can push against it to make your ship go. This is why Science Fiction writers tend to invent reactionless drives and magic heat removal. I think gravity manipulation is the most popular modern variant of these Handwaving schemes. Once you have a scheme the problem of mass is easily trumped by even more power. Basically how its solved by a nuclear submarine.

Sadly real space doesn't work that way. The Rocket Equation is horribly non-cooperative.

NH said...

So now this Laser Star needs electrical power for its weapon so it has dedicated a large amount of mass for the ability to create and harness electrical power. Thus its potential Mass Ratio is constrained by all this mass that has already been included.

So most concepts envision an electric drive of some sort. Since these are reaction mass efficient and this at least lets you use the reactor for something other than the Laser. The problem is thrust. The Electric drives are thrust anemic at the best of times. The Laser Star carries huge amount of mass .. thus it becomes thrust laughable. The Laser Star may take months to effectively change orbits and move towards engagements. There will be no effective vector changes during any combat. The ship benefits from a decent Delta Vee though.

However if you think of the engagement window being something relatively small like the zone between Low Earth Orbit to Lunar Orbit, it really seems to be a weak propulsive system. A Thermal drive would work so much better. Thermal drives like NTR or Chemical Rockets deal with heat by throwing the reaction mass out the back of the space craft. Simple. This is only workable because of the engagement window. These ships can change orbits in hours and make useful combat vector changes.

Now you could use a thermal propulsion system on the Laser Star .. But here is where the rocket equation gets you. You need a comparable Mass Ratio as your opponent to compete with his performance but you are lugging around all this mass on the wrong side of the ratio. So you need a huge honking amount of reaction mass/rocket fuel.

Enough Mass that your opponent could, with a similar mass budget, have huge numbers of missiles, or many times the number of spacecraft as you.

The decision, barring any F35 parallels, will generally be based on economics and practical reality for the mission to be performed.

NH said...

Cordwainer in response to comments/concerns

Breadcrumbs don't matter. If everyone can already see you at IR frequencies, seeing you at RF frequencies is irrelevant.

The missiles will work exactly like spacecraft do. We can reach Saturn orbit with a space probe, we can hit a Helicopter with a shoulder fired missile, and we can do everything in between.

----
RTGs are sub-critical nuclear batteries. They are much less mass effective than nuclear reactors.

There is no advantage to spacing out many reactors as opposed to using one until you have reached your maximum sized reactor you can lift/build.

Chemical power can be used, such as fuel cells or the often mentioned explosive power. However those will limit how many shots you can have. Once you are out of fuel you can't shoot.

----
There is no semi-conductor PV technology that will not behave like semi-conductor PV technology. Now or in the future.

Having a huge mass/area/volume of Solar panels seems to be a detriment on a combat spacecraft.

----
The size Laser you want is of course up to you, however it seems to me that the Laser needs to be big enough to be a credible threat to the Missile armed competing platform.

----
I think you are overstating the Kessler effect. Reading about it over and over in this thread. I cant help but think that Iraq must be completely covered on every square inch by scraps of metal from all the bombs we dropped. I think perhaps instead you can sweep for debris in between battles with systems purposely designed for such a purpose.

Not all the battles will take place in LEO and beyond that volume reduces the problem by simple math. If all battles take place at LEO just put your Lasers on nuclear submarines and space them out on the Earth's oceans. Or on 747's and fly them around at 30,000 feet.

NH said...

Thucydides..

One thing the giant Kinetic Stars vs Laser Stars get bogged down is the basic propulsive performance of the spacecraft become irrelevant due to the presumed Laser ranges.

Since the Moon is only 1.3 light seconds from earth, if you presume a range approaching a light second, then any mission in earth orbit becomes more like an artillery engagement.

These are ranges beyond anything Star Trek has done since TOS. The only Space Opera I am well familiar with regularly even deals with ranges like that is Weber in his Honorverse stories. Where he imagines spacecraft with hundreds of gees of acceleration ...

At those sorts of effective ranges, then of course the speed of the Laser Beam now becomes ultimately decisive. Since crossing the "kill zone" becomes impractical.

Now all design considerations change due to the fact that no other weapon system can match the Light Second Beam of death on a quantitative basis.

I believe it was Tony who pointed out that a lot of this depends on assumed capabilities.

In all likelihood if the Light-Second effective Laser exists, there is only one kind of combat craft. One that uses a Light-Second Laser. All other military craft become transports.

However if the Laser's range is closer to say 10,000 km. Then you get more of the debate Cordwainer and I have been discussing.

NH said...

That should read

Now all design considerations change due to the fact that no other weapon system can match the Light Second Beam of death on a *qualitative* basis.

The quantitative basis is the scheme to defeat the Laser by throwing massive amounts of kinetic weapons at it. Something that becomes increasingly effective the shorter the Laser's effective range.

Geoffrey S H said...

"Given the size of RBOD's (kilometre sized electron beam injectors for a FEL weapon), having mounting points for missile batteries (busses carrying SCoD's) seems to be a relatively straightforward fix, separate laserstars and kineticstars might not even exist."

But you did say 'thousands' of the things might be needed to overwhelm A defence. Thousands of small objects adds up thousands of small mass units. Its a veritable Mass Effect.

The way I see it, you will only have kinetic stars in the RBOD era/techlevel if they can either provide cheap support to laserstars, or (if they are expensive) if they can eliminate a laserstar with minimal effort through handwavium laser-armoured scods. The risks of going up against a craft that has a chance of shooting down your only missile wave whilst possessing unlimited reserve shots is just too great.
In the latter senario, small kinetic support stars would be the only option. Its like carriers being escorted by (but also protecting) Iowa class Battleships.

Thucydides said...

Two comments to the comments ;-)

Nuclear fission reactors are indeed far superior to most other forms of energy generation due to the high energy density of nuclear fuels, but if the energy is being extracted using a Carnot cycle, then much of the advantage lis being lost with all the plumbing and extra machinery needed to deal with the waste heat.

Probably the most remarkable example of waste heat management was a three part series on the Unwanted Blog discussing the "Nuclear Light Bulb", where uranium plasma was running at an incredible 23,333 K. At this point, the issue is actually material science, since materials tend to flash to vapour at that temperature. http://up-ship.com/blog/?p=6694

A much more practical design would be the dusty plasma fission fragment reactor, which offers the promise of expelling charged fission fragments from the reactor nozzle at about 1% c. For higher thrust, you could inject water or other remass into the particle stream, or you could extract energy from the charged beam at very high levels of efficiency, vastly reducing the radiator size. Since you are not Carnot limited, the possibility exists that energy extraction could be in the 80-90% range.

You are right that a laserstar festooned with SCoD busses would be carrying lots of extra mass, but given the huge size of the things, there will be a temptation for the staff to utilize the space, and in any event, they will probably be carrying their targeting drones into battle (releasing a cloud of sensors up to a light second in diameter around the constellation.) A much more probable suggestion is the Laserstar carries a battery of SCoD's as a form of CIWS to blast at incoming SCoD's, so the laser has a much more reasonable number of targets to deal with.

Of course no one is going to be able to jump directly to RBOD level weaponry, so early military spacecraft may resemble multi-role fighters carrying racks of bombs, air to air missiles and a rapid fire cannon (for the spacecraft replace with long range drones, short range missiles and whatever the most powerful practical laser is in that era). Strategy and tactics will evolve a lot as well, as lasers gradually become more powerful and engagement ranges reach out farther and farther.

The only missile weapons that could reasonably exist even in the era of a RBOD would be something like a nuclear pulse ORION capable of accelerating at 100g to push the SCoD busses quickly into battle and cover near interplanetary distances in a reasonable time frame. (One estimate is 15 million kilometres in 5 hrs, or Earth to Mars in about one day). Launched from outside the "one second" zone around the constellation, they will fill the space with SCoDs and ensure the RBOD's are fully occupied, giving your constellation some time to deploy and engage. (don't forget these things will be coming at you as well....)

Geoffrey S H said...

"Of course no one is going to be able to jump directly to RBOD level weaponry, so early military spacecraft may resemble multi-role fighters carrying racks of bombs, air to air missiles and a rapid fire cannon (for the spacecraft replace with long range drones, short range missiles and whatever the most powerful practical laser is in that era). Strategy and tactics will evolve a lot as well, as lasers gradually become more powerful and engagement ranges reach out farther and farther."

Small question that is quite important to my world building efforts. I am trying to avoid RBOD in my world building, partly due to the fact that I'm not sure we can build something like that in the next few centuries. Do you think that its plausible to see such things absent from the battlefield for the next 800 years or so? I know its an extremely odd question to ask, but I would like to check with the experts that there aren't any near-future ways to construct such a device.

NH said...

Thucydides said...

Nuclear fission reactors are indeed far superior to most other forms of energy generation due to the high energy density of nuclear fuels, but if the energy is being extracted using a Carnot cycle, then much of the advantage lies being lost with all the plumbing and extra machinery needed to deal with the waste heat.
----------

It is a comparison thing really. Even limited by a Carnot cycle, and only utilizing a fraction of the available energy and dealing with all the radiative cooling issues; It is still is going to beat out all ship local non-nuclear power generation once a certain power range is needed. On a mass per watt basis for extended power generation.

More efficient Nuclear Power schemes of course will be even better at this, further relegating more conventional power sources to auxiliary uses. However we are talking further and further out into the future.

This is why I proposed that the first generation of space warships would dispense with these sorts of weapons in the first place. It eliminates the need for the Nuclear Power source, letting the ship operate on 1960's electrical power budgets. A RTG or a limited Solar array works great when power needs are modest.

To be more clear I think that Lasers, Rail Guns, Coil Guns, particle beams, etc are all weapons that would only come later, once it was determined the power demand was justified.

It might be certain weapons like Lasers and Rail Guns are well established on Earth for quite some time before anyone bothers putting them on a spacecraft. The space realities being that much different.

Interestingly this sort of limitation also seems to be present in the scenario presented by Geoffrey S H.

------

For the light-second laser "world" I would probably propose dispensing with the spacecraft altogether, mounting large Lasers on the Moon and Near Earth asteroids instead, allowing the defender to avoid the mass problem altogether perhaps allowing for a significant targeting range advantage.

Compare a spacecraft with whirring pumps for cooling and associated other mechanical noise and its targeting issues to a Lunar station with a much larger Mirror, a much bigger reactor and solid ground beneath its "feet"

If in the Light-Second Laser world the Lunar Laser is a 2 Light-Second Laser instead, then every Laser Star is completely outclassed by the local "land" batteries.

Thucydides said...

If you mean "near future" in the sense we won't see a RBOD in the next 20 years, then the answer is "maybe".

Frankly, laser weaponry and laser technology in general is evolving at a rapid rate because lasers are so useful in so many applications. NextBigFuture had a post last week about using lasers to replace spark plugs in an IC engine to promote better fuel economy, to give you an idea.

The US military is already moving to advanced prototypes of 100kW laser weapons for warships and aircraft, and Israel is preparing to introduce "Iron Beam" into service (a laser weapon optimized to shoot down incoming rockets and mortar rounds). Even if making a laser larger than 100kW is problematic (for whatever reason), the ambitious will simply gang multiple lasers together. An array of 10 100kW lasers sharing the same adaptive mirror might look like a plate of spaghetti below decks, but the target isn't going to know, and in a fraction of a second, won't care either.

In fact, gangs of lasers might be the way most ultra high power laser applications are done, from launching laser thermal rockets to zapping incoming ICBMs. If an individual module fails, the overall output is only affected by a small amount, whereas a RBOD built around a single kilometre long liniac and FEL will be a very expensive target if something fails.

Based on the other commenters, the main sticking points are conversion efficiency (near term RBODs will have to deal with monstrous amounts of waste heat), as well as the engineering issues of highly accurate optical trains and mirror pointing (especially if fast slewing rates are needed). A possible work around, which would limit the ability to create a RBOD for your story, is that high power lasers are single shot explosively pulsed units mounted on drones or missiles, which are destroyed as part of the firing sequence. By convention, the weapons crews call these weapons "Frikking Sharks", although very few of them are aware of the origin of the term ;-)

Thucydides said...

NH

I agree that for the "20 min into the future" scenarios, a space platform equipped with modified missiles will suffice, but nuclear power plants are so attractive for the reasons you state that there will be an almost irrisitable urge to "go nuclear", even if the various space powers need to launch them clandestinely.

The dusty plasma fission fragment engine is about "30 min into the future", and since it combines high energy density, massive ISP and low mass (dispensing with the Carnot cycle machinery and limitations), I can see that becoming the preferred means of powering spaceships and their internal systems, so potential space warships will have plenty of energy for railguns, lasers or whatever other sort of electrically powered weapons you care to use. Neutral particle beam weapons might be a good choice, since they have relatively high conversion efficiencies, reducing the waste heat issue when you are in a firefight.

While a "ground" mounted RBOD on the moon or an asteroid is quite conceivable, it has the same issues that shore mounted artillery had back in the day. Being fixed (or if a real rail gun mounted on a railway carriage, limited to wherever the rail lines went), you cede the initiative to the mobile platform. If you have a two light second range, my constellation will manoeuvre 3 light seconds out, wait until orbital motion shifts the shore mount's point of aim and then come in at an unprotected angle. If you have lots of fighting mirrors to cover any conceivable angle, then I might just try to overwhelm the ground mount with a million SCoDs or drop a huge honking rock on it (courtesy of an old asteroid or burnt out comet nucleus).

This will be a very expensive game for both sides, but offence and defense are a constantly evolving game.

NH said...

I am not sure in the Light-Second Laser world you can avoid ground mounted systems so easily.

If you used the two figures I gave, 1 second for the space weapon and 2 seconds for the ground weapon. Then the ground Laser has a range of over ~600,000 kilometers. What time is the right time wait at 900 km and then rush in with massive warships with anemic accelerations? The Moon will most likely have rotated back into a favorable attack angle before the mobile ships get into range. +300km is a lot of space to cover.

Seems difficult, you would need to have some sort of long term plan where the fleet travels at some sort of transfer orbit from wherever to just precisely arrive at a favorable angle at a range of less than a light second. The Fleet perhaps crossing their collective fingers the ground Laser can't be taken down and moved in the months of advanced warning it would have?

Still, granted, it makes good military sense to have multiple lasers on the moon and Near Earth Asteroids. Perhaps even on the top of tall earth mountains. Basically having overlapping coverage of all approach angles.

Since they wont be limited by spacecraft type limitations they will be able to be higher power and fire more often. Ironically also probably be cheaper since they wont be spacecraft.

The networked RBOD's can be leveraged to facilitate Laser Thermal propulsion systems throughout the Lunar to Earth orbital space. And any debris or earthrise view blocking weather satellite can be completely destroyed at a millisecond's notice.

I am not sure this sort of space combat would make a good story. It would be like dueling observatories locked in a perpetual IFF query, razing anything that seemed a threat. Since obviously in a light second laser world you will never see more than a few pixels of any enemy. Better make sure all your credentials are in order before carting that H3 back to that orbital anuetronic fusion development space lab.

Still if you can have overwhelming force in your favor, history has shown that is the route most often favored. With regards to space advancement Dr Tyson calls it the "I don't want to die" driver.


NH said...

errata- He3 and about 600km

I don't necessarily buy the sub-munition RBOD idea exactly. It seems that even in a fairly advanced future a Laser with a Light Second Scale range will be an expensive, complicated, and large device. Not well suited to being miniaturized. In any case they wont match the "big guns" I don't think.

Of course a fighting mirror could be placed on a missile to allow some range extension perhaps.

Either way though the opposing force will destroy those as soon as they come into range. The computer targeting system will likely humorously ignore the Dr Evil protestations of the opposing fleet computers.



Geoffrey S H said...

It seemed to me that RBODs are like nuclear weapons, so powerful that misusing them invites disaster and international condemnation. Use smaller weapons like we do now instead of resorting to wmds to resolve international conflict. You can have the wmds in place, sure, but smaller craft that won't accidently fry a load of commerce satellites and short out information systems of the schools and hospitals below are probably a better bet.

Of course, with 3d printers there probably won't be any real traffic in space any way (small passenger traffic excepted), but some small mobile combatants might still be a better idea than rbods.

NH said...

Seems like there are multiple variants of RBOD being used here.

I was referring to Lasers capable of effectively targeting and destroying things at a substantial fraction of a light second in distance.

I am sure combat lasers will exist in the "near future" I just don't think their capabilities in that time will justify putting them on spacecraft even if there are combat spacecraft, due to the power problems I brought up. A missile will just be easier.

A 10,000 km range Combat Laser for example would be pretty damn impressive laser by our modern standards to be sure. But in a scenario where the laser ship can only fire once every 10 seconds, 3 missiles can defeat it at a 1km per second relative closing velocity 100 percent of the time.


NH said...

Hmm I think my math is quite a bit off. The 10k km Laser would be a lot more impressive than that.

That would only be for a 10km laser in that scenario. Or a 100km Laser with 10kps closing velocity.

My mistake. I plead too much space opera as my only defense.


Thucydides said...

I would suspect that any ship capable of powering a RBOD would have a very impressive amount of energy for combat manoeuvres as well, even if they dump remass into an energetic beam drive for combat. If my ships are only capable of a fraction of a "g", then I will be taking a much different track should I decide to go to war in that case.

My apologies if it seemed I was suggesting a missile with pulse driven laser warhead was a RBOD. It would certainly be more powerful than an on board laser, since there would be no heat rejection issues, but after a certain power level, the ship board laser could take advantage of sophisticated technologies which would not fit aboard a missile.

A ground mounted laser will have advantages as noted, but the ultimate disadvantage is still going to be limited field of view, while a fleet can be concentrated at the time and place of the commander's (and owning polities) choosing. How this plays out will depend on a multiplicity of factors, which is where the skill of the respective commanders (and in the here and now, SF writers ;-) ) that counts.

Eth said...

"A ground mounted laser will have advantages as noted, but the ultimate disadvantage is still going to be limited field of view, while a fleet can be concentrated at the time and place of the commander's (and owning polities) choosing. How this plays out will depend on a multiplicity of factors, which is where the skill of the respective commanders (and in the here and now, SF writers ;-) ) that counts."

There is a scene using that in Through Struggle, the Stars.
They don't have RBOD yet, and missiles and lasers are pretty much evenly matched (and used) - but there is a combat between a superior-range ground installation and a fleet of warships.
The ground installation is only on one point of the planet, so the attacking ships use a highly elliptical orbit to close in. The ground lasers have the advantage of range and power, and use multiple buried mirrors for each emitter to offset the mobility problem. The warships use missiles to draw fire away from them to close range with successful orbits, and to try and overwhelm the lasers.
Interestingly, the buried mirrors means that ground installations can take far more shots than warships, if slagging the entire region with WMD isn't an option: Warships can only shoot mirrors that have already shot them, while ground lasers can directly shoot warships. Even with intelligence, they still have to destroy multiple mirrors if the emitter is shielded enough or of unknown position.
As often, defence is cheaper and more powerful, while offence can concentrate more resources at the same place.

This is a case where the planet isn't entirely controlled by one single force, though. If you can put lasers all around the planet, then the limited angle problem goes away.

Another variation on this scenario are with high-dV (and patient) attackers, using a fast, close fly-by instead of elliptical orbits. Then, they can come as close as they want and go as fast as their dV budget allow to minimize time at enemy range.
This also makes attackers' missiles harder to stop, but also defenders' ones, so this is assuming a bigger advantage on lasers (or one would simply send the missiles at the planet, not the ships).

Eth said...

Also, what is the max range of a bomb-pumped laser?

If there is no max range, then missiles can stay relevant by going big and act as one-time RBOD drones, depending on the compared costs.

At first, the winner is the one with the most bombs.
But then a slight range advantage can make the difference, and decoys become viable if drives are cheap compared to the bombs themselves. And fitting some of the decoys with cheap, short range bombs. Lasers may be used as point-defence against those, if the higher cost is justified by their ability to fire several times.
Also, a single bomb can potentially generate multiple beams to aim at several targets.

If we go beyond light-second range, at some point random movement also becomes a defence against beams for the drones. An unmoving ground installation would probably still have higher range and numbers to compensate.

NH said...

Where I think the sub-munition missile will fall down is Targeting and Mirror/Lens size.

Laser diffusion calculations are based on mirror sizes from what I can see and that leaves the advantage progressively to the big laser star and the bigger ground station.

Eth,

I think in the 10,000 KM world(which is evidently a really good Laser range for orbital combat) you are right the Ground Station is pretty limited by its angles and its locations.

But at the 2 Light Second Range world that problem goes away because a Lunar Laser could target an opponent hundreds of thousands of KM past the opposite side of the earth.

Its a bit like a sniper in a bell tower. If he has a shotgun he is very limited, you can maneuver all over the place to avoid getting shot. If he has a .50 cal top end sniper rifle, your ability to do becomes effectively limited only by LOS.

So the Light Second World fixed stations might have so much range that even though they are fixed they are extremely effective. Keeping in mind that approach vectors are pretty limited by themselves beyond a certain range. It maybe cant hit you now, but it can hit you in say 17 hours even though you are still can't hit yet with your laser.

Thucydides,
Not necessarily though. It seems that you could have hundreds of Gigawatts of thrust power on a He3 fusion powered craft and still have less than a decigee of acceleration. If the Atomic rockets list is any guide Newtons of thrust is pretty low compared to chemical rockets. While the idea that maybe it still could maintain containment with a much higher mass flow sounds good, it will still be limited by the huge distance it has to cross.

I think that when you start to get Light Second Ranges "Earth Orbit" conflicts begin to make a lot less sense to to the extreme ranges of the participants.

The whole Fusion "torch" idea for a ship is interesting. In that it basically assumes you have a magnetic bottle with a small hole in it. Which evidently is quite a challenging problem. The ability to have a variable hole would suggest an even harder problem.

This would apply to most Anti-matter concepts as well.

Maybe you could vent Laser Coolant as an auxiliary thermal drive.

NH said...

I think range is kind of the scale that will judge these things.

For example as suggested a laser which can only kill at 100KM is fairly limited. Although probably great for sweeping debris in LEO and all sorts of Earth conflicts. That Laser should be pretty mobile to be of use. A Lunar version is kind of useless. And ship's acceleration and ability to effect large combat vector changes matters a lot. A handful of Missiles though will be quite a threat.

At 10,000 km range Lasers probably will be decisive over missiles. You are going to need to fire large amount of Kinetics to defeat them. But the fixed Laser is pretty limited. Good for guarding parts of LEO from mountaintops in addition to providing Laser Thermal thrust for various applications. But 10,000 km is just too short of a reach to really blanket orbital space from Earth to the Moon.

At the Light Second/2 Light Second ranges, Lasers dominate over any weapon. No one can match the speed advantage of C. And fixed bases have such an awesome range their drawbacks are mitigated.

So in between those there would be a huge gambit of possible balance considerations.

Targeting becomes a bit issue here. Since you "see" your opponent in IR, I don't know what that means if you want to "shoot" your opponent in UV.

It seems like you can make long range lasers in IR wavelengths but it requires big mirrors because of diffusion.

Perhaps you see your target in IR, "Paint" them with a diffuse laser in the wavelength you want to use, then use that active sensor type of feedback for the big shot.

Thucydides said...

I suspect that the actual "range" limit of RBODs will be one light second, simply because with increasing range the speed of light delay between seeing the target, taking aim and firing will become a problem. Even a ship with a limited drive will be able to apply a random thrust vector and shift enough to be missed past one light second, unless the RBOD also has an unreasonably wide beam.

In one of the blogs, (Atomic Rockets or Rocketpunk) there is a discussion of using lasers at "scorch" ranges, where the beam has diffused enough due to distance that it no longer has the power to burn through ship components, but it would still put a lot of thermal energy on the ship, messing up heat rejection systems and causing the ship to take some sort of evasive manoeuvre to avoid overheating (maybe a "barbecue roll"). With the RBODs being discussed, the scorch range could be up to a light minute (!), so engaging a laser weapon or installation does not have a "hard" cut off, but gradually increasing amounts of energy being deposited on your ship as you approach.

Bomb pumped lasers need to be more carefully defined than we have been doing so far. The unspoken assumption is there is some sort of chemical explosively pumped generator driving the laser, but the ultimate expression of this idea was the Excalibur X-ray laser project for the Strategic Defense Organization. I really have no idea of what the projected range of an Excalibur was supposed to be, but it was probably in the thousands of kilometres, and could sweep the sky from GEO to the visible horizon if all the laser rods could be deployed and aimed effectively. Using a nuclear explosive to drive your laser weapon might have negative secondary effects on any of your spacecraft nearby (especially EMP on ship and drone systems).

High energy lasers using shorter wavelength light can have smaller mirrors, but I suspect they will retain large mirrors to seek out targets using their own thermal emissions. Once you "see" the target, you can boresight down the same mirror and unleash the UV beam. This won't work for an xaser RBOD, since the x ray beam would interact with the individual atoms of the mirror, but a diffraction grating would allow you to focus the beam. A series of telescopes on the laserstar and off board sensors provided by drones and the other ships of the constellation would provide a detailed 3D picture of the target before you zap it.

High thrust, high ISP drives like ORION nuclear pulse drives or pulsed fusing drive rapidly "imploding" pellets of nuclear fuel at a high rate (like Project Daedalus) would certainly provide the sort of performance needed to do many "space opera" type missions (just getting from point A to point B would be nightmarish otherwise). A laserstar using this sort of propulsion system would need the optical train to be isolated from the ship on a sort of raft, like nuclear submarines isolate the ship's machinery from the hull to reduce noise and vibration being passed into the water.

And it may be possible to have high levels of power on a spaceship relatively soon if this Lockheed project works as planned: http://www.physics-astronomy.com/2015/02/lockheed-martins-new-compact-fusion.html#.VPZg1il7Y73

Like a lot of the proposed Aneutronic reactors, this is a small piece of machinery (said to be about the size of a jet engine), although unlike the aneutronic proposals it is Carnot limited, so if you are thinking of using this in a story there will need to be pumps, boilers, turbines and all kinds of other things for the "black gang" to keep running. Even a "small" spaceship using this as the power plant would be the size of a 747 (and have 747 sized "wings" as the radiators).

NH said...

It will probably be more of a trigonometry problem than some hard cut-off at a 1 second light delay.

Overall vector vs possible vector changes. After all even 1 gee of acceleration only lets you change vectors by 10 meters in a second.

A truly high Power Laser could have a fairly wide beam at longer ranges and cycle it rapidly for a very short period of time. Allowing it to combat vector changes vs delay.

A sort of staccato strobe light .. machine laser shotgun as a metaphor. Scorching and damaging rather than killing. Likely the actual parameters might be based on expected performance of the ships in service.

The downside of Orion and other explosive drives is .. no whopping electrical power generation capabilities from the propulsion system. Thus they are inherently inelegant design wise for Laser Stars. Although it should be possible to have a nuclear reactor and an Orion drive on the same craft, and bring the Laser Star into "life" at an earlier technological development stage.

I am always dubious of Mr Fusion in a box stories. Lockheed Martin not really any more credible than the rest in my experience. I am still waiting for their SSTO space-plane.

fro1797 said...

It seems that much of the topics that have been discussed in this thread have been covered before, in earlier posts. As to the heat problem, a solar panel would radiate heat from the anti-sunside, with only relatively small radiators to assist. Nuclear reactors would need larger radiators, probably about the size of the solar panels. As with most things, there would be a progression of more and more sophisticated weapons, driven as much by political needs as by technological advancement. Range and distruction increase in fits and starts, taking decades or even centuries to reach the RBOD level of weaponry. Weapons developement is driven not only by what we can do, but what we we are willing to do. Military spacecraft will use whatever power, drive, weapons that they feel is needed, while commercial spacecraft will use the most economical systems.

Ferrell

Eth said...

Tucydides:
Bomb pumped lasers need to be more carefully defined than we have been doing so far. The unspoken assumption is there is some sort of chemical explosively pumped generator driving the laser, but the ultimate expression of this idea was the Excalibur X-ray laser project for the Strategic Defense Organization. I really have no idea of what the projected range of an Excalibur was supposed to be, but it was probably in the thousands of kilometres, and could sweep the sky from GEO to the visible horizon if all the laser rods could be deployed and aimed effectively. Using a nuclear explosive to drive your laser weapon might have negative secondary effects on any of your spacecraft nearby (especially EMP on ship and drone systems).

I was more thinking about PMF or even PFF than near future, where RBOD become possible. So that would more be nuke-pumped xasers - I doubt we can expect any form of chemical bomb pumped laser to compete there.
Excalibur ran into a wall with the chemical explosive fission-trigger shaking the rods before X-ray-producing nuclear reaction began, but we can expect that to be solved. Probably with antimatter-triggered nuke at first, but maybe other methods not depending on chemical explosives (be it with or without a fission first stage) will be used.

AFAICT, fusion bombs scale well, and the reason we didn't go over the Tzar Bomba was because of mass budget on the weapon delivery systems (bombers and ICBMs). But in a RBOD future, we can assume that mass budget is less of a problem, RBOD themselves will probably be pretty heavy. I even remember (but couldn't locate back) on Atomic Rocket a USAF project of putting a giant fusion bomb in orbit on top of an Orion engine, with 3 gigatons of yeild - enough to destroy the Soviet Union from orbit. And I guess you can go pretty much as big as you want with nuke yeild, as long as you can move it afterwards.
What I wonder is how the xaser device scales. Does it become more efficient with yeild? Less efficient? Is there a max or optimal size? Is it possible to make the bomb flatter to increase the beam size?

Another consideration is that you can't use this kind of weapon anywhere near your assets, so neither from surface nor close orbit. Given the low efficiency of such a weapon, firing a 3Gt xaser nuke from low Earth orbit would fry a continent, any close satellite and probably every single unshielded electrical system and cable of the planet. Firing one from the Moon's surface would add a new crater and throw enough fragments around to have Kessler yell at you.
It's not necessarily a big problem with light-second range (simply put them on high enough orbit and clear their neighbourhood) but one that must be planned for.

Geoffrey S H said...

"In one of the blogs, (Atomic Rockets or Rocketpunk) there is a discussion of using lasers at "scorch" ranges, where the beam has diffused enough due to distance that it no longer has the power to burn through ship components, but it would still put a lot of thermal energy on the ship, messing up heat rejection systems and causing the ship to take some sort of evasive manoeuvre to avoid overheating (maybe a "barbecue roll"). With the RBODs being discussed, the scorch range could be up to a light minute (!), so engaging a laser weapon or installation does not have a "hard" cut off, but gradually increasing amounts of energy being deposited on your ship as you approach."

In the context of this the I would argue that RBODs could be seen as strategic weaponry- too much of a threat to the overall neighbourhood to be used.

In a setting involving combat across multiple solar systems, with multiple eggs in multiple baskets, I might think differently. But in the context of a single solar system with extensive civilian infrastructure there might be far too much risk of collateral damage. Its not just the ferrous slug that can travel a great distance and ruin someone else's day.

Present day militaries have nukes but use conventional weaponry. Why use such a powerful and risky weapon when you have something less powerful that could be just as effective.

NH said...

I am not sure I see the reason to avoid the RBOD weapons on political/ethical grounds.

Any weapon is likely to kill a spacecraft really. I doubt it will be like BSG or WW2 Battleships with ships shrugging off numerous blows. So killing spacecraft won't be inherently unethical with one weapon vs another.

There wont be any radiation affecting anyone else really. Even a diffuse beam is a pinprick in the volumes we are talking about.

There won't be any "civilian" casualties outside of the target ship. So that leaves collateral damage out.

Perhaps avoiding the nuclear bomb pumped stuff. That has a basis is current thinking so I can see that carrying forward at least. I am not convinced they will be necessarily all that practical. Thinks I have read suggest perhaps problems with accuracy and horrible efficiency.

Avoiding them in a story because they are boring? I can see that.

Geoffrey S H said...

You are indeed correct. I overthought things there. The only problem with your analysis (with ragard to story writing) is that you have effectively cancelled out any reason to take them out in-story, with the exception of technical difficulties in making the things and the difficulties of heat expulsion/mass etc. Not having them in a story set 500 years + in the future without a good reason why seems like the handwavery that accompanies modern stories not dealing with robots replacing human in combat in the future.

So how does one take such boringly powerful weapons out of a story featuring reduced mass restraints on spacecraft while remaining plausible?

Not that you can't make a shooting match between planets interesting, but there might be very few ways to re-write that basic premise.

If this is going over old ground then I apologise as I've been too busy to read over the other comments. Of so then ignore me.

NH said...

Perhaps 1 Light Second Lasers are extremely hard to accomplish due to accuracy. There is a long list on Atomic Rockets of things that could throw off aim.

Also we don't really know how technology will advance over the next 500 years. RBOD might be thousands of years away. We tend to look at progression in the last 100 years as the new norm and that it will continue unabated into the future. But we really have nothing to base that on.

It could very well be there are plateaus on our road forward, since there are plenty in our past.

In addition there are several things on our horizon which might slow progress. Dealing with Global Climate Change. The apparent backlash against Science.

You could throw in wars, religious movements and the like and easily have a 2500 a lot like what we tend to think 2200 might be like.

As to the Laser effectiveness picking a range that would be good for the "world" of the story, might be enough. It certainly is more plausible than having light second lasers and then handwaving ways to make things interesting again.

A 1000 km range laser maximum with hard science spacecraft might be preferable to say Weber who gives his spacecraft hundreds of gees of acceleration and his bomb pumped xray laser missiles thousands of gees of acceleration in order to be interesting in his world of 2 light second laser weapons.


Thucydides said...

RBODs are not 500 years away, although they are probably not quite "20 min into the future" either. NBF now tells us that the US Navy is busy preparing 300kW laser weapons. http://nextbigfuture.com/2015/03/us-could-ramp-up-miliary-lasers-by-ten.html.

Interestingly enough, one of the designs under consideration is a gang of 6 commercial cutting lasers, so there will have to be a lot of handwaving to say high power lasers are not going to be part of your world.

WRT Orion pulse drive, the *minimum* size of ship considered viable by Dyson and Co was about 4000 tons. Since Orion gets more efficient with scale, later designs that needed to be boosted to orbit by Saturn V were considerably less efficient (lower ISP and performance). In a 4000 ton Orion there is plenty of room for a nuclear reactor or two, and if small fusion reactors are developed, I'd cram as many inside as possible for redundancy and to have a massive amount of energy for whatever I wanted to do.

A Daedalus type fusion drive actually gathers some of the drive energy via interactions between the magnetic nozzle and induction coils. Most of the energy is to power the ignition laser or particle beams, but there will be plenty of energy while the drive is running for a laserstar.

WRT Excalibur xaser weapons, there are several work arounds even in the here and now. If all the lading rods are ganged together (think of drinking straws in a package of 200 in the store), the aiming and control mechanism could be considered the "box" and the pumping device a golf ball attached to the end. For a certain amount of beam dispersion, the lasing rods could be arranged in a shallow cone, but still fixed in place by the framework (the entire package has to be shifted to aim). While not as "economical" as the initial Excalibur device, the 1980 version needed to economize on the "physics packages", hence the sea urchin design with multiple independent lasing rods. And of course if you are a fan of Niven and Pournelle, don't forget Footfall, where the Orion drive was co-opted to drive Excalibur packages dropped behind the ship.

But yes, the real issue with RBODs is the "Zeroth" law of Space combat; people are not interested in reading stories about missile busses and robot weapons, regardless of how realistic they are. Maybe the crunch point in the story is the Marines running down the gun battery line looking for a cooling leak or trying to get the spare fuse installed before the Martian Republic spaceship gets in SCoD range...

Eth said...

NH:
Perhaps avoiding the nuclear bomb pumped stuff. That has a basis is current thinking so I can see that carrying forward at least. I am not convinced they will be necessarily all that practical. Thinks I have read suggest perhaps problems with accuracy and horrible efficiency.

I can see nuclear fears holding nuke xasers for a bit, but it becomes increasingly unlikely with time passing, particularly if RBOD and nuclear drives are also developed. I can see conventions forbidding them near civilian assets (as in, nowhere near LEO), if only to avoid collateral damage.
Accuracy should be solved sooner rather than later, and horrible efficiency isn't a problem when you are pumping that much energy. Even a 1% efficiency laser from a 239 Mt bomb would be a 10 000 TJ laser beam (the Meteor Crater impact energy) - and those are conservative figures.

Eth said...

NH:
Also we don't really know how technology will advance over the next 500 years. RBOD might be thousands of years away. We tend to look at progression in the last 100 years as the new norm and that it will continue unabated into the future. But we really have nothing to base that on.

It could very well be there are plateaus on our road forward, since there are plenty in our past.

In addition there are several things on our horizon which might slow progress. Dealing with Global Climate Change. The apparent backlash against Science.

You could throw in wars, religious movements and the like and easily have a 2500 a lot like what we tend to think 2200 might be like.


Technologically, RBOD doesn't seem that far out. With unlimited budget, we could probably build one in a few decades, starting today - albeit a massive, unwieldy one. The biggest obstacle seems to be the size and wealth of the space industry needed. Assuming a big enough system-wide industry from the other side of the PMF (or its interstellar equivalent), the only way to prevent RBODs is if no-one found the need to put in it the equivalent of what we put in nukes last decades. Which means there is no major war on sight between great powers, or that said great powers are legalistic and trustworthy to have conventions against them and follow them. And probably don't feel existentially threatened.

However, technologically, I don't see what kind of events could set us back enough bar global collapse. The tools we use today to run the world (computers, high-tech industry...) are the same that are used to maintain and develop technology, so whatever knock them down will turn things into a post-apocalyptic future.

Climate change is hard to evaluate given the IPCC isn't even remotely apt at its job, but even 1200 BCE-level climate chaos would probably not set us back centuries (again, barring global collapse). Our standard of living, stability, security and industry would take a hit, and technological progress could be offset for several decades, but that wouldn't be enough. The industry hit would slow down space development, but the end result would simply be a later space age, not a different one - though with more time, technology may be even more advanced once we get there.

Similarly, I don't see how religious movements could do better (or rather, worse). What we see is that fundamentalists taking power:
- Turn back toward old-time barbarism and as such, are doomed to loose against their opponents (Daesh)
- Try and keep up, including tech development (Iran, North Korea). They are less efficient, both because of they loose access to much of the international tech community, their more limited resources and the inherent inefficiencies of fundamentalist dictatorships. Even then, I can't see those system being stable for centuries given that they tend to have lots of enemies and massive internal problems. They could theoretically stall tech development if one (or a few) managed to take global power 1984-style, but I can't see that happening before we get RBOD.
- Play nice with more efficient, non-fundamentalist powers (Qatar, Saudi Arabia). This means there are non-fundamentalist powers in the first place, and it tends to work only as long as the other power has something to gain (like petroleum) so I don't see it being stable in the long run either.
Now, fundamentalist movements like Creationists or Degrowth proponents can try and block specific tech domains and maybe slow it down globally a bit, but it's hard to have a movement just big enough to block things but not to take power for centuries. At some point, it will either grow to one of the above cases or shrink to relative ineffectiveness.
In any cases, the only way those could be strong enough to significantly slow tech development down.

Eth said...

Backlash against science is either from the above movements or a bit overestimated I think. Sure, some people go against vaccines, and that's a public health problem, but the effect on vaccine development has been negligible so far.
My perception is that those backlashes we see are a reaction to a 19e Century-style scienticism we've seen resurging last decades (which itself is a reaction to the failure of the XXe Century great ideologies). Both (along most above movements) are symptoms of the problem more than its cause, and again I don't see how they how they could slow things down enough without simply collapsing the system.

Then again, a post-post-apocalyptic space setting could allow for pretty interesting assumptions. To start with, the new civilisation would have access to enormous theoretical knowledge but most easily-accessible resources would be either depleted or in the form of (potentially dangerous) ruins to be recycled.

Eth said...

Thucydides
Interestingly enough, one of the designs under consideration is a gang of 6 commercial cutting lasers, so there will have to be a lot of handwaving to say high power lasers are not going to be part of your world.
Would that work for extending range? I assume those lasers wouldn't be coherent between each-other, so how would decollimation be calculated in this case?
Btw, would multiple beams from a single bomb be (or be made) coherent between themselves?

But yes, the real issue with RBODs is the "Zeroth" law of Space combat; people are not interested in reading stories about missile busses and robot weapons, regardless of how realistic they are. Maybe the crunch point in the story is the Marines running down the gun battery line looking for a cooling leak or trying to get the spare fuse installed before the Martian Republic spaceship gets in SCoD range...
If we can make a chess mach tense and interesting, I can see a RBOD/BPX match being made tense and interesting as well, with each 'player' (either individual commander or command crew) wondering what will be the other's move, what are its exact long range/short range/decoy compositions...
At a higher level, it could be about admirals battling for superiority through entire systems.
basically, replace Space Battleship Yamato + space fighters and its crew by Task Force Yamato + drone constellations and its staff.

Also, I can see it being used for a spy fiction, given the importance of intelligence in this kind of battle. It could even be a 'countdown to Armageddon'-style spy fiction where NATO and Soviet ICBMs are replaced by Federation and Alliance RBOD/BPX.
The advantage is that, contrary to its Cold War counterpart, you could have the war starting without it being Game Over yet: contrary to ICBMs, RBOD constellations primary targets would be enemy RBOD. So the countdown wouldn't be toward some guy deciding to push some red button but toward when one of the forces would arrive at destination - and punch its way through the other force with exchanges of Dantean energy lances.
Not what I would call boring.

Eth said...

Another thing about BPX (Bomb-Pumped Xaser): planetary atmospheres aren't transparent to X-rays. So a xaser would be ineffective against ground installations. It would still probably cause a high-altitude explosion and an EMP against Earth, and maybe some nasty cascading radiation to the ground? But an UV ground RBOD would probably be fine.
So for atmospheric planetary attack, you would still need UV RBOD.
This could help conventions against the use of BPX near planets, though they would still be effective against airless worlds.

NH said...

Rather than going backwards I was suggesting more of a plateau.

Global warming might make us focus our technological development in ways not very conducive to space development. Consider even a successful utopian style "full sustainability" type culture puts a damper on colonizing space in the first place.

Disease is potentially a big one. Already antibiotic resistant super-bugs making the mainstream news with people dying of them. A bit of a quiet info that's been under the surface of hospitals for the last few years.

Considering this will come at a time where hundreds of millions of people could find themselves without food .. there could be some pauses in Space utilizable nuclear reactor development.

The War on Science is an interesting one. It might hit countries at a budget level. Climate deniers, Anti-vaxers, Intelligent design proponents, Moon hoaxists, a push to increase fossil fuel use, and so on. It all seems poised to send us down a track that is not following the upward trend of the last century.

War in Europe actually looks possible for the first time in decades. What does that say for our future development speed? The last time both sides didn't have ICBMs.

Some suggest the real financial collapse was just stalled in 2008 and we could be looking at a complete crash of the system ..

As to the Lasers - the RBOD is actually 3 problems, not one.

The first problem is Power. As you mention this one is probably solvable soon.

The second problem is diffusion. No cutting Laser right now exists that isn't a big search light beam at any real space type of range.

The third problem is accuracy. Once you focus (reduce diffusion) the beam it makes it a lot harder to aim after all.

It isn't till you solve those 3 problems that you can worry about putting it on a spacecraft.

NH said...

I think the problem with RBOD in light second ranges and boredom comes in because the two sides Moves are glacially slow compared to the speed of the weapons.

If your Task Force accelerates at 0.1 G but its weapons can hit at 1 Light Second, which is probably realistic for an advanced fusion powered RBOD Laser Star scenario, your moves will take weeks and months to accomplish.

There is a reason that works with long ranges have spectacular propulsion performance. Andromeda is another one that played with Light Second Ranges.

Or they make ranges short so you can have highly acrobatic dogfights. Ala Star Wars Star Trek, Babylon 5.

Or they just insult our intelligence and have very long ranges but short range dogfights like the cinematics in Mass Effect. Why Dogfight with Mass Drivers that reach 0.02 C?

The problem is when you have a LS RBOD even a 5G orion drive is pretty weak sauce for the sorts of maneuvers that seem more "interesting"

NH said...

Xray Lasers can't use mirrors, I believe. Which might limit their accurate range a lot.

Weber avoids this by focusing them with artificial gravity. A neat trick but pure handwavium.

Geoffrey S H said...

"I think the problem with RBOD in light second ranges and boredom comes in because the two sides Moves are glacially slow compared to the speed of the weapons.

If your Task Force accelerates at 0.1 G but its weapons can hit at 1 Light Second, which is probably realistic for an advanced fusion powered RBOD Laser Star scenario, your moves will take weeks and months to accomplish. "

Its worse than that. If you have long effective ranges then there is little reason to manoeuvre at all.

If we say that getting to mars will take centuries (alto of discussion on this site convinced me of that), then we may find infrastructure remaining in earth orbit. Even if you move much of it and military constellation bases outside of lunar orbit, you still only have to nudge the constellation slightly inwards to engage the enemy on the other side of the planetary system.

If you assume that earth and mars are well-populated yet balkanised, then the only manoeuvre occurs when a nation on earth engages a nation on mars. Otherwise its just a set of artillery pieces on either side of the gravity well 'lake'.

I'm trying to work on this but the problems remain difficult. Extensive laser blinding by both sides might reduce effective ranges somewhat...maybe.

Eth said...

NH:
Rather than going backwards I was suggesting more of a plateau.

Yeah, I can see a plateau being plausible. I remember Rick calling it a 'decelerando' in an old post.
Such plateau wouldn't have to be in all sciences, even. For example, medical or computer sciences could have great advances that wouldn't translate to space development sciences. And indeed, better wind generators wouldn't help it either.

That said, if we already assume a well-developed space infrastructure, RBOD wouldn't need that much new techs. Massive industries and enough wealth to refine existing techs would end up with RBOD, which is what a centuries-old, system(s)-wide infrastructure would necessarily have the means (assuming it is not in decline). The three problems you point out could be solved with enough refinement (and money thrown at the problem) without needing game-changing breakthroughs (which may still help considerably, of course).
So at some point, there will RBOD available if conflicts are big enough to justify them at the given time.

There may also be civilian installations for energy transmission and/or space propulsion by laser that could be repurposed as RBOD in a pinch as per the Kzinti lesson. I can even imagine such installations specifically made to also be efficient defensive RBOD by prudent/paranoid powers.

What I originally wondered there was, once you have RBOD, could BPX take on the role left by now-obsolete kinetic projectiles - and if so, what would battles look like?

War in Europe actually looks possible for the first time in decades. What does that say for our future development speed? The last time both sides didn't have ICBMs.

On this particular point, I'm sceptical about risk of a true major war. Russia wants its former Soviet bits back, sure, but they aren't ready to fight Europe's big armies for it. Europe wants to keep Russia out of its eastern bits, sure, but they aren't ready to throw their armies at Russia for it. And no side wants to risk the kind of escalation that would lead to nuke-throwing.
Interestingly, Russian war strategy is adapted to that, doing its best to invade the bits it wants while using (flimsy) excuses to make a direct military intervention from NATO diplomatically difficult:
https://medium.com/war-is-boring/nato-is-acting-like-its-1985-63a54c2c4ad2

Also, while Russia and Wester Europe armies suffer from serious budget cuts, Poland probably has enough of an army now to punch Russia in the face should they try to invade back that far, and both sides know it.
(That's not something I would ever wish for the future, but it could make for a pretty good story. One that the Poles would love to read about.)

That said, we may have similarly devastating results if a new world war erupts, without nukes or even conventional battles: such a war would be fought through Internet first, and it is simply not robust enough to survive world war-levels of cyberfights. Given our reliance on Internet, its disruption would cause the same economic damage than the previous ones.
And contrary to conventional or nuclear wars, there is no guarantee that world powers are prepared for or even conscious about the risks of escalation there. Again, kind of like the previous ones.

But on a narrative side, one has to be prudent as war, resistant diseases and/or catastrophic economic fall/climate changes could easily go from slowing things down to the fall of the entire system.

Thucydides said...

Scenarios involving some sort of civilizational catastrophe need to be examined very carefully as "world building" since the second and third order effects are the ones which usually are the ones that end up driving things in unexpected directions.

The "ur example" of unexpected effects is cars. Leonardo da Vinci drew recognizable self propelled vehicles in the late 1400's, and the first self propelled road machine was made in 1769 (followed very shortly by the first car accident...). So cars were predictable and predicted for centuries, but no one ever predicted suburbs, drive throughs, "parking" with your girl/boyfriend, strip malls or any of the other things that cars brought in their wake.

If you are unlucky, you will end up with "fridge logic" questions for your readers, like "where did Lord Humungus get all the gasoline for his gang to drive around and threaten the only oil refinery left? (Mad Max 2: The Road Warrior).

WRT high energy lasers; ganging six cutting lasers is a quick and dirty way to radically increase beam power. I suspect the US Navy is worried about budget in the near and mid future, so having a low cost way to put 300kW lasers aboard ships is a very pressing issue for them right now. Issues like beam quality can be worked out in time, but for the moment a high power beam is the most desirable quality they are looking for.

Here are two more articles that demonstrate the age of RBODs isn't as far away as you might imagine. The first article is a project to gang lasers together and ensure the beam(s) are in phase, enduring a high quality, high power beam. The second one is about a solar powered megawatt class laser. If you can use concentrated sunlight to pump a laser of that power on Earth, then building one in space where your mirror can be illuminated by much more sun without worrying about nightfall, clouds or rain, then a space based solar laser is quite feasible anywhere inside the orbit of Mars. (Beyond that, the size of the mirror is probably so large that it becomes impractical for any sort of mobile or military purpose. Still, a vast gang of mirrors to drive a laser launch system might be a cheap way to do things in the outer system).

http://www.ia.ucsb.edu/pa/display.aspx?pkey=2943
http://nextbigfuture.com/2014/10/solar-powered-lasers-for-magnesium.html

Finally, massive RBODs and other futuristic superweapoons might invoke a response much like Russia against Ukraine, Georgia and (potentially) the Baltic States. While they still have a large conventional military to threaten and distract world leaders, much of the "real" action is hybrid warfare, using propaganda, cyber, economic threats and selective use of SoF (Russian Spetsnaz operators command squads of "rebels", effectively multiplying their manpower by 4 to 8X, depending on the number of rebels per squad).

So while the RBOD on the far side of the Moon can effectively clear the Hill Sphere around Cis Lunar space, a team of Martian commandos disguised as ComiCon attendees arrive at Tranquillity City prepared to sabotage the stock market computers, put some nasty virii into the air system and assassinate a few key political and economic leaders.

Eth said...

The problem is when you have a LS RBOD even a 5G orion drive is pretty weak sauce for the sorts of maneuvers that seem more "interesting"

I think it depends on the medium and focus.
Sure, a movie with a Mass Effect-like plucky starship having adventures wouldn't work well for space engagements.
On the other hand, it's far easier to decorrelate the pacing of a book from the in-universe time. A sentence can describe a microsecond cyberattack from one AI against another as well as an hours-long manoeuvre to position a laserstar constellation.
Similarly, having a constellation of drones 1 Ls away don't work well on screen, but it makes little difference on a book from a turreted Space Battleship belly-lander.

So instead of writing about the captain fighting a Space Destroyer on his Space Submarine, or the pilot on his Space Spitfire outwitting the enemy on his Space Messerschmitt, one can write about the commander outwitting a planetary RBOD swarm with his expeditionary RBOD constellation (through a subtle game of intelligence and counter-intelligence, decoys, choices of range, power and price for RBOD, drives for 'drunkwalking' and when to use them, how much dV they bring...)
Whether they stare at screens light-seconds (or even minutes) from each-other or see the blank of the eyes of their opponents, whether the fight lasts a few seconds or a few months, I frankly don't see why it couldn't be compelling.

I think the failing is that we instinctively want to speak about such battle like the ones we know about. So warships exchanging (lazor) shells. Planes dogfighting with (lazor) autocannons. Even infantry ducking it out with (lazor) rifles and (lazor) swords.
This is the same reason why 1900 SF was talking about air battles as flying dreadnoughts ducking it out. And if you had told them it would be closer to big mechanical birds with guns, they would quite possibly have equally struggled with how is that supposed to be interesting. "So they fly at one-another, and then shoot at each-other until one takes a bullet? How boring."

Also, if your drone's cross-section is small enough (say, 10m), 5g is enough to avoid a beam at 1s. If it's not small enough or the beam is too large, you can go for 2 or 5 Ls, at some point it becomes enough. It won't change much narratively as such, as it would be random movement with no human input in the pattern. However, given that dV is limited, there may still be human input in the tactics with when to begin drunkwalk manoeuvres.

Xray Lasers can't use mirrors, I believe. Which might limit their accurate range a lot.

They can't use conventional reflection mirrors (or lenses), but they can use the same kinds of mirrors used in X-ray telescopes based on grazing reflection on multi-layered material (which is why they look like long cylinders instead of disks). A laser is 'simply' a telescope where light goes the other way.
(Courtesy of Atomic Rocket: http://www2.lbl.gov/Science-Articles/Archive/multilayer-mirror-optics.html )

Geoffrey S H said...

So I guess that mobile laserstar vs mobile laserstar combat starting from bases within earth orbit at around 5 light seconds or so is unfeasable. You'd have to have each party starting out at bases about a light minute out for a setting to make any sense.
Kinetic swarms would have to possess torch drive engines to cross the distance sufficiently quickly... unless a laserstar provided support scorching enemy sensors and making it hard to track to swarms.

Geoffrey S H said...

...Outside earth orbit I mean. Ugh.

Another question: Can anyone here see the uses for a laser that can mission kill at around a light hour (barring the elimination of 'stationary' orbital targets)? Could you 'walk' laser fire over predicted vectors of an enemy constellation, or is it too difficult without handwavery and ftl sensors?

NH said...

The Xray Laser then wouldn't be able to use the IR targeting mirror.

As I understand this the whole targeting thing boils down to the ship shining like a beacon against space in IR so you point your mirror/telescope at it. Then fire at the image.

Separately spotting and targeting adds an additional calibration variable to the accuracy problem.


NH said...

Geoffrey I was wondering the same. Since you know they wont be able to accelerate very fast for long, you should be able to basically walk or pepper the general area with Laser shots along possible vectors.

The ships wont be able to rotate in 1 second, Their high accels will be only along their long axis. No high acceleration drive will last realistically more than a few hours due to the mass flow requirements (or mass of bombs for orion) So leading them should be possible. Especially if you have a range advantage.

NH said...

Maybe Mars invades Earth...

At the absolute longest transit point between Earth and Mars the kinetic bus ships launch. They have some very efficient drive system designed to accelerate the whole way to earth. This is to produce as fast a closing velocity as possible. The mission is a flyby the missiles will never orbit the earth. The missiles themselves are cheap solid chemical steerable rockets that number in the millions probably mass produced on 3D printers or something. Maybe they are seeded with some much high performance Xray laser bombs to add some kick. Just Before they come into Laser Star Range the buses push them outward into clouds dispersed enough the Lasers cant make multiple soft mission kills with diffused beams.

At a much shorter transit point the rest of the fleet leaves. It will accelerate and decelerate with a goal to orbit the earth. This fleet will include troop transports, atmospheric drone carriers and robot troop transports.

The goal being to saturate the Earth's Laser defenses with Millions of kinetic targets and then pick off the survivors with Mars' own Laser Stars.

NH said...

Maybe the missile bus fleet slingshots around Jupiter first to pick up velocity. Or Jupiter then Saturn. Or Jupiter then Neptune then Jupiter again.

At 100 Kps relative You need a lot less missiles to overwhelm the Earth's lasers than at 50 kps. At 300 Kps you need a lot less. And so on.


Thucydides said...

Using off board mirrors and drones to identify targets and aim the RBOD isn't a particularly difficult operation, we do very much the same thing now with UAV's, scout helicopters and other off board sensors to direct missiles and bombs from aircraft, and instead of stately movement mediated by Newtonian mechanics, aircraft deal with violent and unpredictable movements in a very unforgiving and cluttered environment.

In fact, a fully deployed constellation will probably span a light second (once again to minimize communications lags and reaction time), and possibly have hundreds of sensors of various sized spread across the volume, giving everyone in the constellation a detailed 3D view of every potential target in sensor range. Once the order is given to go into action, the number of effective sensors could jump massively as the missile busses and SCoD's are deployed and start sending their observations back to the constellation.

I believe the fastest "unpowered" speed in the Solar System is 72 miles per second, any faster and you reach Solar escape velocity. Sending a SCoD or a comet against a target at that speed will generate lots of excitement, especially if it is coming against the direction of orbital motion around the Sun (antispinward). A burst of engine power as the projectile closes, with drunkards walk evasive action and dispensing submunitions and penetration aids will give the RBOD a difficult problem to deal with.

NH said...

Whoa ..

Aiming 1 Light Second Laser Beams with off-board spotting "isn't particularly difficult?"

We don't do anything like that at all. Spotting for a modern artillery piece on Earth is not even in the same zip code as that.

Without some serious explanations of how it will be accomplished, I am a bit stuck at... Its a big telescope you fire a Laser through.

Believing it will work with some other Telescope and the actual firing Laser can't even focus on the image itself? On a completely different wavelength no less.

Sounds like a calibration nightmare of epic proportions.

Up to this point everyone but me is suggesting Passive targeting after all.

Thucydides said...

No, it is not difficult at all, simply a matter of triangulation.

If you are including all the sensors available to the constellation, then you could have a baseline potentially a light second across, and accuracy to almost any arbitrary level of precision.

Offboard sensors here on Earth have much more difficult conditions to contend with, and *we* can put rounds through individual windows on buildings.

NH said...

Still not buying it. The in the future they will do more concept isn't really necessarily valid.

In this particular case the "sensor" being used is a image obtained by Infra-Red on a mirror. In the same way that a telescope is. This is a passive sensor. It is an image created by photons in the infra-red part of the spectrum.

Now previously at this point you would fire the laser directly at the image "shoot down the boresight" you mentioned. Through the wonders of optics the mirror will transfer the photons of the Laser along the exact opposite path along the mirror to the target. So if you can see it, you can shoot it.

Now instead we are triangulating. Computers in the fleet will evaluate the image. Barring some giant leap in analog computing it will be a pixelized image. So multiple ships in the fleet are comparing images and their computers are translating it into coordinates for the ship to fire at.

So far so good. That is sort of what we do "now" sure. You get coordinates to within some level of precision. Then you point the firing ship's laser at the target. You are trying to point a perfectly straight line at 1 light second. With a spacecraft. With reaction thrusters.

So we are assuming that the Laser Star's attitude control is basically so precise we can adjust the heading of the ship or its laser or its mirror by micrometers. Maybe more likely nanometers or even picometers. You would have to do the math but one light second is a very, very long hypotenuse.

Now what can go wrong here? Lack of Pixel resolution. Lack of fine adjust granularity. Any error when multiplied through the size numbers we have here becomes huge.

Firing artillery into some volume say anywhere within 1000 KM to hit your window, 1,000,000,000 cubic KM (1000 km cubed) is a heck of a lot easier than firing into a volume of 27,000,000,000,000,000 cubic kilometers to hit a spacecraft.

In the needle and haystack terms, the Space Haystack is 27 million times larger than the Earth one.



NH said...

I suggest the problem is one of calibration. The 1 light second calibration problem is millions of times more complex than the 1000 KM artillery one.

The straight needed in the straight line is a lot less forgiving.

Assuming the Triangulation Coordination was successful in the first place. There could well be some calibration challenges there as well.

Eth said...

For precision, you can use interferometer telescope swarms. So you are still comparing pixels, but with a whole lot more of it.

For mirrors, you can use deformable mirrors to orient them, instead of thrusters or even reaction wheels. I wouldn't be surprised if we manage stupid amounts of precision there as well, like atom-sized. Today's deformable mirrors are pretty good, and we're talking at the very least PMF there.

And this is, of course, barring some new tech we can't think about today arriving in the next centuries.

A constellation with multiple mirrors sounds like a smart idea to me. You could in some cases go further than 1ls if the forward (and middle) mirrors have access to the pseudo-random algorithm used by the emitters, so they can still drunkwalk.

Geoffrey S H said...

So essentially the main aim in such a battle is to take out the mirrors on the front line rather than the laserstars at the rear.

Eth said...

Also, you can close in or send more mirrors, to compensate for the loss of mirror drones. Or try and keep your expensive emitters out of harm's way, depending on the situation - I am assuming a mirror drone is cheaper than a reusable emitter, and a one-time emitter probably wouldn't need mirror drones.

Thucydides said...

Triangulating is so dead simple that it was used on warships and coastal batteries in wet navy warships (and the mathematics was understood in gunnery manuals dating back to the 18th century, even if the techniques of the day were not able to take full advantge of this). The reason battleships and gun cruisers in the age of steam had such tall superstructures was to mount optical rangefinders which used triangulation to range the main guns.

A RBOD with a huge liniac powering the FEL xaser optical train (which is the example from Atomic Rockets) will be able to mount its aiming mirrors on the ends of a truss .5 to 1km in length for its on board rangefinder, and then add the constellation's drones and other warship's sensors to provide a very granular and detailed picture of the target array.

I hadn't thought of it, but this is basically Eth's "interferometer telescope swarm" as well, so the Constellation gunnery officers will have a mass of data, long, clear sightlines and targets that cannot manouevre a great deal (as noted, even a 5g ORION cannot move very far in relation to the distance covered by a RBOD beam).

NH said...

There are two problems:

One is triangulation. Which I think you may be downplaying at 1 light second. The triangle is going to look a lot like a line. But I already conceded you probably can triangulate given adjustments.
------

The other is shooting straight enough to hit a target you have NO active image of on the Xaser focusing "mirror". which was the bulk of my concern.

There is no "firing down the boresight" with the Xaser using Passive IR images picked up on Mirrors.

So basically you have a blind sniper you are telling where to shoot. And hoping his muscle control is sufficient to adjust the rifle true.

This works at 100KM with artillery. I was willing to give you 1000KM. But we are talking about 300,000 KM now.

Keep in mind this is the focused, non diffuse Xaser RBOD we are discussing. Heck call the Laser Spot 1 cm in diameter.

How this problem became "simple" when its never been demonstrated to have ever been done really is stretching my suspension of disbelief.

Then we not only can hit an enemy spacecraft this way but small missiles by the hundreds of thousands. So the Laser Ship is having to make lots of tiny tiny (very tiny) adjustments to how it has the Laser Pointed.

And we can't use a atomic level bendy mirror. If something like that exists in this era, because the Xaser can't use a mirror. The Xray equivalent to a mirror will need to be atomic level. Or perhaps worse, since the whole reason the Xray Laser doesn't work is it bounces off the atoms on the mirror. So maybe subatomic level??!

And your error in any of the process better not exist. Even a tiny rounding error is gigantic at 300,000 km.

When you are "firing down the boresight" you are aiming at an image that is only a few meters away. Its an application of observatory technology.

This other is a different engineering problem.

The Xaser RBOD seems like it will be much harder than any spectrum that can use a mirror. Given that as Thucydides said you can use different frequencies on the same mirror. One for the image (IR) and one for the beam (something else).

NH said...

Triangulating tells you where the target is.

It can't make you shoot straight.

Geoffrey S H said...

There is also the fact that anyone on the front line will have to wait about 2 seconds for their orders to produce results. Constantly firing the artillery laserstar and just shifting the beam on command to overcome this problem could make it vulnerable to blinding lasers seeking to overheat the radiators. You may therefore need laserstars at the front to provide fire instantly. If there is a fault, it can be fixed there and then by people that it needs to be fixed for.

Factoring in NH's commentary on the difficulty of such a task in relation to missiles and I can see a need for artillery laser stars firing through mirrors at targets that can't move (thrusters knocked out) but which can still shoot back. Smaller escorts focus on missiles (and spin around to fire at retreating constellations if both groups are to pass by each other) and possibly have a mirror on their backs for the artillery laserstars to fire on (combine the mirror and the escort and you get something well armoured which can do the spotting and shooting simultaneously). Larger 'heavy infantry' laserstars at the front do the on the spot firing.

NH said...

As a thought.

Since it seems that IR to UV spectrum lasers will be easier to use. In my opinion anyway for reasons I mentioned. Then it could be Xasers need Xrays bouncing off the target.

Active sensors. Which will allow them to now "fire down the boresight" like the other Lasers.


Since the bomb pumped lasers are Xray because of the whole concept. That would suggest there would be an attempt to paint the target with xrays to improve accuracy that was problematic due to calibration.

A ship might be designed to avoid this reflection in some way. Absorbing Xrays instead of reflecting them. Give a modicum of protection from Bomb pumped Laser's - at least reducing their effective range.

Geoffrey S H said...

I had a thought regarding regenerating armour. If you have gimballed thrusters, you have a mini-turret that might have a very wide 'firing' arc. What if you designed them to also spray self-sealing foam when called upon? Use them and well-applied thruster power to apply foam to the hull have a hit is sustained (after you've rolled over to shield the hole from further fire of course). Then rotate back with the semi-healed wound. Not a perfect solution, but better than nothing.

Eth said...

NH:
If something like that exists in this era, because the Xaser can't use a mirror.

Why not? X-ray telescopes have been using X-ray mirrors for decades. I see no reason why a Xaser couldn't either.

NH said...

Well according to this anyway..

http://www.projectrho.com/public_html/rocket/spacegunconvent.php

The very end of the section about Lasers, right above the particle beam portion. Evidently it is an energy problem.

So the Xray machine can. The RBOD can not.

Also its not sufficient for it to be a "mirror" It has to be the same mirror you can see the enemy ship on. In this context we were discussing IR images.

At least for the "down the boresight" type of situation.


NH said...

*Telescope not Xray machine, sorry.

NH said...

Keep in mind I am also not saying it would be impossible to sight with one telescope and mirror and fire and hit something with another "mirror" system. even at a range of 1 light second.

What I am objecting to is the way it is being dismissed as some sort of trivial matter.

Thucydides said...

If Bob Forward can suggest hitting a moving target in the Alpha Centauri system using a Terrawatt laser system orbiting Mercury and a fresnel lens thousands of kilometres in diameter in the outer solar system without raising any eyebrows, then using a FEL Xaser to blast targets one light second away is indeed "trivial" in the sense it is using well known and very old technology (triangulation) and applying the generation after next technology to the application. This is more evolutionary than revolutionary.

In the PMF, I suspect there will actually be 3 fairly common laser threats: high frequency optical lasers mounted on warships; large ground mounted lasers for thermal rocket launching, tuned to whatever wavelength is best absorbed by the remass, and bomb driven Xasers mounted on missiles to attack "hard" targets by overwhelming the defense or armour with a huge pulse of energy delivered in a fraction of a second. The ground mounted lasers would evolve into the "two second" range weapons.

PFF RBODs will use diffraction gratings to aim and focus the beam (as per Atomic Rockets), since at the energy levels needed for a RBOD even glancing the beam off a sheet of lead would simply have the beam interact with the lead atoms individually, with disastrous results.

Warships or orbital installations that might be targeted by RBODs might well be built in the form of a giant rotating torus covered in layers of regolith, radiation shielding and water (the water helps absorb and redistribute the thermal energy being absorbed by the outer layers). Such a lumbering dreadnaught will need a pulsed fission or fusion drive just to get anywhere, and a constellation of such ships going to war might be equivalent to the High Seas Fleet steaming towards Jutland...

This is the main weakness of trying to set a war story in the PMF or PFF; military hardware becomes far too expensive to build in large numbers, and holding these ships "at risk" is too much of a risk for most polities; the grand fleets will be parked in hardened asteroids while the war rages around them using other means and forces.

fro1797 said...

I'm thinking that RBOD's would be very expensive to build and maintain. Perhaps only a very few nations would be able to have them. Nations that had them would use them to deture others. A very few nations would work very hard to come up with methods and/or technology to counter RBOD's. Sounds very much like nuclear powers vs. nuclear-wanna-be's we have today. For an example: PMF Callisto feels the need to build RBOD's to maintain their freedom from domination by Earth nations. Mars, because of politics, won't build RBOD's, but needs some deturent to them, so builds Nuclear Pumped Lasers (Excaliber-type X-ray lasers)by the dozens.
Trying to come up with stratagies to deal with RBOD emplacements, might be a case by case study.

Ferrell

NH said...

Consider my eyelids batting at Bob Forward as well. No one has actually gone into how that will work exactly. Its given a pass since Light Sails can be shown to work. And that ship can Steer to maintain a predetermined course. If its course changes it can even radio back the course change and coast for a few months while the Lasers are re-calibrated.

Plus that is a visible light proposition. And actually diffused Laser application.

Also we didnt define RBOD as only Xray somehow that seems to be mutating here. My concern is Lasers that cant actually bring up the image on their mirror and fire down the boresight as it was put.

Triangulation still requires the canons involved to shoot straight. When they miss adjustments are made. You wont see the Laser Miss. A canon shooting straight multiplies error by the distance traveled.

People don't bat their eyelids at Star Trek either. Most of the population believes all that stuff will be possible someday with advanced in technology.

Cordwainer said...

To add my two cents which isn't probably worth that much when we factor in NH's inflation/conflation rate:

1. I agree RBOD's are obviously something that we won't have in the near future, but lasers in the few hundred's of kilowatt range will most likely be feasible in the near future. The tech to cool and manufacture a space worthy weapon are well within modern capabilities.

2. Combat range will be determined by propulsive capabilities of your warships and missiles which in the near future will likely favor a mix of missiles, guns and lasers since most combat will be at spitting distances. The vast distances of space in any era will favor autonomous drones with sub-munitions and mounted weaponry over fire and forget, battery on time(triangulation) and seek to kill systems.

3. Kessler effect and "space junk" will be an issue in both orbital space and deep space. In fact it will be harder to track and avoid in deep space. Such an issue may necessitate the building of sweeping technologies, which may in themselves necessitate the development of "laserstars". Anti-collision armor may become a necessity for space vehicles which will also effect space vehicle design and weapons design.

4. Spacecraft propulsion will be dependent on several major factors which will include, heat dissipation technology, access to in-situ resources, effectiveness and affordability of space launch technology and space-based infrastructure/industry.

Cordwainer said...

To comment on the fourth point I made previously, feasibility of propulsion technology will inevitably determine combat range for warships.

Near future will be interesting. I imagine laserstars used as debris sweepers which would be pressed into an orbital defense role. These would consist of a large parasol like ramming shield in front of the ship with lasers mounted around the edge of the parasol. Propulsion could be a hybrid solar-thermal and solar-electric system and power generation would likely be solar powered since the solar panels would largely protected from collisions by the parasol shield.

As for "ships of the line" these would likely use commercial transport designs for NEO transport that would likely utilize liquid fueled micro-rocket or pico-rocket arrays or some type of ion/mass driver propulsion system. These would offer ease of production from in-situ resources, good heat dissipation characteristics, low power generation requirements and decent throttle control for fuel efficiency.

Deep space exploration will require the development of more sophisticated propulsion systems eventually. While you could do a one way trip to Mars or automated mining of the Belt using current propulsion technologies, if you want to engage in two-way commerce and transport then you will need better technologies.

The technologies I think most suitable would likely be FFRE's and pulsed fusion or fission fusion propulsion systems like, Mini-Mag Orion, MSNW's liner fusion or PuFF. Solar power has limits as it gets further from the Sun and when in shadow, while NTR's offer little advantage over conventional chemical propulsion when you factor in heat dissipation mass, mass needed to launch in orbit and maintenance needed to perform in space. While the danger to humans might be in if a nuclear reactor has a bad day is less in the vastness of outer space, the cost to maintain a reactor in space may not be economically feasible compared with other options. Dusty plasma FFRE's and pulsed nuclear propulsion systems would only require a nuclear reactor if they plan on maintaining a long period of continuous thrust. For most transits they would only need to be used for short periods of thrust that could easily be provided for by solar power or Stirling RTG's.

Such an early era would likely involve slow moving vehicles and some moderately fast space vehicles with a limited ability to perform evasive actions but also a limited ability to pursue enemy craft. Such a scenario would likely prefer guns in battery fire at long range and lasers at short range over missiles and drones. Drones with sub-munitions might be preferred over missiles and would likely be used at short to medium ranges due to there greater survivability and ability to pursue and evade enemy countermeasures. Dual mode "sprint" missiles that act as guided weapons at short range and battery on time or area denial weapons at further ranges would also be feasible.

Cordwainer said...

In terms of early era space navies whether expendable or not drones and the craft that carry them will be an expensive features of a space navy just as they are in terrestrial navies.

Dual-mode missiles will have limited range and be more expensive than simple gun based artillery, although the capability of dual mode systems will likely make up for cost. Where gun-based systems would be better is in smaller craft where the mass savings would allow for better range and maneuverability.

Lasers are most likely to be used as sub-munitions or as point defense on craft with large payload capabilities, while guns will take over point defense roles for smaller craft.

I tend to think early era space navies will likely have a great deal of specialization in ship types due the fact that commercial designs with modular payload bays will likely be used as the basis for some warship designs and that differences between the function of those commercial ships will also effect how those ships are armed and used. For instance large payload haulers may be more functional as specialized vessels that are a part of a fleet than a "do-it-all" design. Smaller shuttle vessels designed for carrying cargo between a gravitational body and an orbiting freight vessel might lead to carrier type vessels for such shuttle-craft. Shuttle craft could act like artillery tugs that would carry and emplace automated weapons in advance of an enemy fleet position or long distance snipers and short range escort interceptors for fleet defense. You would also need support vessels and fuelers. It might be best to have shuttle carriers that carry fuel for shuttles and other craft in the fleet and separate shuttle/fleet tenders that carry extra fuel and replacement munitions for shuttles and fleet craft. Shuttles could also be used to carry munitions between tenders and other vessels in fleet to restock their stores between battles and carry up munitions from terrestrial locations to the fleet.

Cordwainer said...

As for early-early era space combat your going to be even more limited to orbital munitions and most likely pressurized water propulsion systems with the water either carted up from Earth or mined from lunar sources. Hypergolic and cryogenic fuels for station keeping are costly and not easily come by or produced in space. Using water as reaction mass makes the most sense and you can always mount a reformer on your space station to turn that water into hydrolox fuel for your satellites kick motors. Mass producible SRB's in all sizes from micro-SRB arrays for kick motors and orbital maneuver systems as well as large SRB's for terrestrial boosters also seem quite feasible to me.

So early-early warfare would include terrestrial launched drone craft and munitions, orbital artillery, space station and lunar/NEO mounted drones, missiles and artillery. As well as faster moving cryogenic or hypergolic fueled vessels used as "troop" transports that would likely carry robot soldiers not human soldiers. Such soldiers would be designed to act as "space marines" for attacks on terrestrial bases and unprotected orbital equipment as well as for boarding actions against space stations.

Thucydides said...

Of course while designing splendid constellations of laserstars, kineticstars, support ships and a grand flagship for the admiral, the annoying little man in the back is yelling something about what is the economic basis for these future colonies to build fleets, and what are they fighting about?

Those constraints are probably far more important than what sorts of weapons systems will the constellation deploy?

fro1797 said...

If I remember correctly, as many wars were fought for idealiological reasons as were for matterial gain...or simply to keep their independance/ property/territory...a colony that evolved from a string of permanent research stations might feel a bit threatened by a radical new political party back on Earth that espouses "Pan-Humanity" one speices, one government. Just a thought, but if researchers' kids get bored, perhaps they might do something a little more sophisticated than a lemoade stand...and it escolates frome there. Three or four generations later, you got a real colony and people suddenly wonder where the thell that came from.

Ferrell

Thucydides said...

For a change of pace, an absolutely gorgeous short movie which gives you a visual idea of what the PMF may look like:

Wanderers: https://www.youtube.com/watch?v=Q6goNzXrmFs

Geoffrey S H said...

In light of the discussions on laserstars, I would be interested t know the opinions here on the future of naval (sea) warfare over the next few centuries.

fro1797 said...

Serface warfare in wet navys might move away from large combatants to smaller, more agile units with lasers and rail guns being the main weapons, with missiles and ordinary guns becoming secondary. More reliance on drones and long range combat. Submarine warfare and littoral warfare capablities increasing. Increasing dependance on obital based intell and tactical reconn.

Ferrell

Geoffrey S H said...

Interesting. Surface combatants are already quite small (excluding carriers of course). Most navies tend to have frigates around 3000 tons. Do you think they will get smaller than that?

I can imagine wave-skimmer missiles increasing in importance, with the only high altitude craft being hypersonic.

Eth said...

On one hand, ship classes tend to go bigger and bigger, and that since more than a century.
WWII battleships were bigger than Dreadnoughts. Modern destroyers are bigger than WWII destroyers.

On the other hand, some ships, including the big ones, tend to become obsolete. Battleships are not used anymore, at the time of cruise missiles, aircraft carriers and nuclear submarines.
Aircraft carriers are an exception, as they are not only still useful, but they also became bigger, partially because jets need longer runaways.

We can see here the importance of tech shifts: missiles made guns obsolete, and with them the massive battleships that were using them. Nuclear attack submarines are a near-unstoppable threat to even the most escorted carriers, hence why part of the massive escort is about trying and stop them - or rather, stop second-grade attack submarines.

But here, we also see the importance of what the navy is used for.
In a major sea war, aircraft carriers would be made obsolete by first-grade nuclear attack submarines. They are capital ships today because first-grade navies don't fight each-other.
This is probably the case because of nuclear balance, but it is possible that, say, Japan (and then the US) and China come to blow, which could become a major naval war between first-grade navies, but limited enough so nukes aren't used (as no side would be existentially threatened).
Even India and Vietnam are trying to build regional first-grade navies (even if limited in size for Vietnam), precisely to counter China.

So maybe the world will become increasingly divided and subs will hunt everything paint in grey, and we will see the end of carriers, and of ships patrolling outside of their controlled waters, and more subs (and ground-based aircraft) trying to keep control of said waters.

Elsewhere, we have Iran relying on high-causality low-budget swarm tactics to counter big expensive Western warships, which prompt the US to develop anti-swarm tactics - namely lasers and escort drone boats. If Iran had been an US ally/neutral, we wouldn't be seeing such developments.

So maybe Iran and nations in similar position will become/stay less hostile to first-grade navy owners and we will see such efforts be limited to a few US and Israeli initiatives - or rather, converted into lighter anti-piracy police duty.
Or swarm tactics will become more prevalent, and lasers and drone escort will be on any independent ship or task force.

Also of note is the usage, both today and historically, for police work: keeping seas (particularly high-traffic lanes) safe of pirates and smugglers. And occasionally search-and-rescue jobs that no-one else can do.
This is the job we see navies focus on when they are not distracted by fighting each-other (and they have the budget for it).

Then there is the Russian navy that has to pull itself back from rust hell with an uncertain economy ; the European navies that, with continued budget cuts and no major war in sight, are giving up more and more of their long-range capabilities (France and to a lesser extent the UK are keeping some power projection, but mostly for emergencies) ; Japan that may or may not go for the world stage ; the US whose navy will suffer hard from the F-35 and the LCS debacles as well as the inflated costs of the Zumwalt (and frankly, who can take such an ugly ship seriously?[*]) and will probably have to tone their 7-seas peacekeeper role down, to the displeasure of many lesser powers that are counting on them for it...
And that's just for the next decades.

[*] This may or may not be the subjective opinion of the author, and aesthetics may or may not have an effect on warship capabilities

Eth said...

But here are trends I think will stay mostly true for the next decades, and maybe the early PMF:

More drones.
We are seeing it today, and it's probably a lasting trend. Drones are full of advantages, even if you don't care about human lives: Pilots/operators are expensive to train, and as such are expensive to loose. Drones are lighter and as such more capable. They aren't limited by human endurance. They aren't afraid. There are tasks where drones are less limited by the number of human operators (a swarm could be controlled by only one operator for a task)...
And automated systems are more efficient, so getting rid of the human operator (or rather, keeping the human supervisor safe) is an obvious move.

What could limit drones:
Increase of jamming/hijack strength compared to electronic defence could make drones useless. Maybe not close support ones, though (harder to jam/hack a short-range link).
A vast increase of EMP tech compared to electronic shielding tech. We'd have to jump to non-electronic drones, which would set it back for decades. I don't see this one coming, but who knows?
Political backlash - at some point, having "killer robots" could get such ill-reputation that international conventions are passed against those. Maybe if drones with a bit too much autonomy murder a bit to many civilians of the wrong side? This need not to be absolute, but for example forbidding "autonomous lethal decisions" aka. decide to shoot by itself without an operator pressing a button.

Eth said...

Ship types:

If the world become more peaceful, navies will put more emphasis on small, versatile "police" ships, equivalent to today's frigates.
Some may carry light drones for varied tasks, some may even have on-board commando for SWAT-like interventions.
I wouldn't be surprised if they got even lighter, and if part of their duties were given to light, extreme endurance plane and boat drones.
If the world become globally more safe and prosperous, there would be more emphasis on search-and-rescue, disaster relief and other humanitarian jobs as well, as there would be less criminality on seas.

If we continue to see insurgencies as the biggest form of conflict, we will continue to see power projection be favoured.
Today's big aircraft carriers may be used for big planes like radar planes in addition to drones for ground attack and air superiority. Or disappear completely if planes get a big autonomy boost or are replaced by satellites. Drones could be given to smaller, cheaper ships like amphibious ships or escort ships (frigate/destroyer equivalents).
Amphibious ships are there to stay in one form of another. They are basically a land base on the sea, with QG, hospital, troop transport, helicopter(/equivalent) port... But this one can be moved around faster and safer than building a land base at the right place.

If several big nations are at each-other throat, then I'd expect more submarines. Subs will continue to be deadly and invisible, and invisibility is the best of defences when any weapon can potentially one-hit-kill.
Subs have less in the way of ECM, but stealth makes up for it I'd say.
I'd expect to see swarms of drones for intelligence gathering, and weapons depending on the effectiveness of anti-swarm weapons.
No submarine drones, as water makes it hard to communicate (and stay discreet). Fully autonomous submarine drones, though - that's a scary thought.

A variant is conflicts between first- and second-grade navies. First-grade navies may invest in cheaper surface warships, relying on their superior technique to be an effective defence while second-grade navies would search for unorthodox methods, less regards for losses and/or high-grade weapons from elsewhere - as seen between the US and Iran above.

I'd expect a mix of the above, varying depending on the situation.
In a cold war, for example, we could have both sides at each-other throats but keeping police, surface and power-projection ships - both by habit and because the other side also didn't invest everything in pure ship-killers.

Another point is the use of space.
If anti-areospace weapons are available enough to get in the hands of reckless forces (like, say, IS), then they may use it liberally against satellites - or rival nations shoot each-other satellites (be it a full war or a latent conflict). Which will probably make LEO unusable. GPS and such may still use GEO, but spy satellites and many orbital weapons are good to go. Even GEO may not be entirely safe.

This would make information transmission more of an issue: less long-range drones, more local headquarters, more scout- and spy-planes/boats...

Geoffrey S H said...

There's something worrying abut the idea that nuclear subs are now effectively completely undetectable. Taken to its logical conclusion, that means that all other surface traffic is obsolete- no transports, amphibious ships. If they are truly undetectable then there will be no point in sending any kind of vessel out unless it is a sub..... so aircraft carrier subs anyone?

Personally I think we will attempt to improve sub detecting systems over the next few decades. Any other option is too expensive or technically unfeasible (see: submersible aircraft carrier) Are laser detection systems viable?



As for Europe- it will either improve its forces or be dominated by Russia. Certainly in Britain there is an awareness that if any more cuts occur then the armed forces will never truly recover. This is about that economic or relative decline, its about the threat posed by Russia. That is something that will probably focus minds... eventually.

Thucydides said...

The main trends that will drive the wet navy are cost and ease of detection.

Collectively they will give rise to "swarm" tactics of smaller ships and versatile weapons (primarily long range multi purpose missiles). Each individual ship might only carry 24 raounds, but losing one ship is far less damaging for the fleet and the opewration than losing a guided missile cruiser carrying 100 missiles.

Advances in material science and power technology will make it possible for small "Corvette" sized ships to cross the Pacific and still be able to fight. and small missiles to be as effective as current Tomahawk or Harpoon type missiles.

Cost will also keep most ship missiles subsonic (supersonic ordinance might be delivered by long range missiles like the Chinese D-21).

Finally, the need for persistance will creat classes of vehicles like solar powered UAVs high in the atmosphere providing overhead surveillance to Waveglider type drones floating in the ocean http://liquidr.com/technology/waveglider/how-it-works.html

Eth said...

Geoffrey S H:
There's something worrying abut the idea that nuclear subs are now effectively completely undetectable. Taken to its logical conclusion, that means that all other surface traffic is obsolete- no transports, amphibious ships. If they are truly undetectable then there will be no point in sending any kind of vessel out unless it is a sub...

That's the conclusion I got - in case of open conflict between first-rate navies, assuming that it's not over in a blaze of hell, they may rely heavily on subs for sea dominance/interdiction, and use surface ships only in safe waters.
Subs would be the capital ship there.

It is interesting to note that once a sub attacks, it becomes easier to spot, and to destroy. It still makes carriers obsolete, as a pack of subs could still destroy them. Even a lone sub could destroy the carrier if you're fine sacrificing it.
This is also assuming no-one will be using anti-sub nukes. But such nukes would make any ship irrelevant anyway, so there would be no more navy as we know it. Nor world, probably.

Also, there would be more variety in subs than today. A few attack subs also carry anti-air missiles, for example (not for self-defence so much as to trol... I mean ambush a coastal airport, for example) - we could see a more dedicated anti-aircraft sub. Similarly, we could see (conventional) missile/shore bombardment subs, drone carrier subs, tender subs (like did the WWII Kriegsmarine), E-war subs...
The main change is that they would be smaller, and less bristling with weapons (hence drone carriers, but probably not aircraft carriers - however cool it was in Macross Zero). And more expensive, also.


What would be the effects of vastly improved sub detection? It could indeed happen in the next decades or centuries.
It could bring the situation back to WWII (where carriers rule) with drone motherships - maybe modern carriers if large planes don't have more autonomy. Or pre-WWII (where battleships rule), with direct-attack ships, be it missile boats, artillery boats (if missiles are too easy to shoot down) or even direct-fire boats with lasers and such (if all projectiles are easy to shoot down).

As for Europe- it will either improve its forces or be dominated by Russia. Certainly in Britain there is an awareness that if any more cuts occur then the armed forces will never truly recover. This is about that economic or relative decline, its about the threat posed by Russia. That is something that will probably focus minds... eventually.

Like the UK, there is an awareness in France (though not from everyone) that military budget is too low, particularly now with the army nearly overextended with only too active theatres with boots on the ground - and that's with the logistical support of the US & cie. And there's the feeling that as far as going on other continents is concerned, they are Europe's army. (That's not a good feeling.)
Whether they can reverse it, aka conduct massive reforms and balance the budget, remains to be seen.

The good news for Europe is that the Russian navy suffered so much from the '90, they will need time to rebuild Soviet-era capabilities.
Right now, they are focusing on coastal defence (they have huge coastlines), then subs (both attack and nuke-throwing). This should already take at the very least a decade, probably more, particularly with the state of their economy.
Then they will invest in niceties like power projection and peacekeeping/police elements.

Given that Europe has no intention to invade Russian coasts and no-one wants the kind of war requiring subs to slug at each-other (and even then, the US would help), it should give a few decades to Europe to stop bleeding their armies white and get a hold on their budgets.
I personally expect Europe to be either fixed or lost at this point anyway.

Eth said...

Thucydides:
Collectively they will give rise to "swarm" tactics of smaller ships and versatile weapons (primarily long range multi purpose missiles).

Interestingly, I've recently found this article about the US making their Tomahawk missile quite more versatile.
https://medium.com/war-is-boring/u-s-marines-can-now-call-in-tomahawk-cruise-missiles-for-close-air-support-2a8aa4a64428
Sounds like a smart move. They produce so much of it, the cost has to have been driven down. Making it smarter has to be cheaper than making a new anti-ship missile. even if it happens to not be as efficient, having more of them should more than make up for it.
And using it as a one-time ground-attack drone is pretty clever as well.

Geoffrey S H said...

@Thucydides.

I would disagree slightly due to the need to add staff/computers and engines to those smaller ships. Some valuable equipment of that nature might be better off in a well-armoured ship. Similarly, small missile of increased lethality might be increased in size to become larger missiles of even bigger lethality, cost permitting. If they are more expensive, put 'em on a larger flagship until they can be used.

The point you make about swarms being able to take losses is sound though. I would therefore take your idea and add one or two large well armoured ships to the mix, trusting in the swarm ships to be the primary target as they are so hard to get a lock on over the horizon. They can be used aggressively, while the larger ship stands back, fires stand-off weapons too small to fit on the swarm ships, and takes any hits that come its way.
As you say, technological capabilities might erase the difficulties small vessels possess in the face of distance. Nonetheless, given the power of pacific and northern atlantic storms I would remain cautious for now. The smaller the vessel, the less capable it will be to withstand such storms.

I would therefore see a future U.S task force (whether submersible or not) featuring around 15 large combatants and the equivalent of 15 more large combatants- say around 45 or 50 swarm ships. If the mission requires an admiral's staff I would definitely have a reasonably well defended flagship (though the coming of the drones may change that).

Geoffrey S H said...

@Eth "Even a lone sub could destroy the carrier if you're fine sacrificing it."

Indeed... could nuclear subs be mass produced enough to match the 'not flashy and numerous' military that the DoD thinks the U.S needs (in contrast to flashy big ticket items like the F35, etc). If not then I would go with a surface swarm ship fleet.

Post pmf though, expendable nuclear subs might be an idea.....

Eth said...

Nuclear subs may be mass-produced, I'm not sure.
Conventional (like diesel-electric) subs, or even pure electric subs if batteries become more efficient, probably could - as far as high-tech ships can be mass-produced.
The main advantage of a nuclear submarine is the enormous endurance. Some nuclear submarines built today are made without ways of refuelling: they are already carrying their nuclear fuel for the next decades.
Conventional submarines can be pretty good subs (and have the slight advantage of being able to completely stop the engine and run on batteries), trading price and not working with deadly radioactive stuff for only weeks of endurance.

Nuclear energy may give a few more tricks to nuke subs, though.
If nothing else, the ability to wait for months in darkness, reducing movement and as such further risks to be detected - but I suspect if the major navies are sticking to nuclear instead of both, there are reason for it. If you take France, for example (I just know them better), despite major budget shortfalls, they are still keeping a reduced pure-nuclear submarine force even though they developed a new conventional sub (the Scorpène) for export.

Otherwise, quite a few of small but technically first-rate navies, like Israel or Sweden, have conventional subs. They don't really need the endurance, after all.

Related: the US seems pretty conscious of the sub threat. Their answer is spamming the oceans with surveillance drone ships:
http://www.defenseone.com/technology/2015/03/militarys-robotic-ghost-ship-passes-critical-test/108352/

Unfortunately, there isn't much in the article about their real detection capabilities. Also, they are specifically talking about diesel submarines. So either nuke subs have indeed a few more trick up their sleeve, or it's because those submarines happen to be from slightly less advanced designs (I doubt Iran has the ability to have quite as good subs as Western nations).

I also suspect they wouldn't survive long a real major conflict, but giving info on the enemy sub fleet prior to (and at the start of) such conflict would probably be quite helpful.

fro1797 said...

Interresting note: U.S. capital ships are, by law, named after States (Ohio Class submarines, for example).

Ferrell

Thucydides said...

WRT smaller ships in the North Atlantic or Pacific, the WWII era "Flower Class" Corvettes (based on a whale catcher) were very small and were capable of operating in the North Atlantic even under extreme conditions.

Displacement:
1,015 long tons (1,031 t; 1,137 short tons)

Length:
208 ft (63.4 m)o/a

Beam:
33 ft (10.1 m)

Draught:
11 ft (3.35 m)

Propulsion: single shaft

2 × water tube boilers
1 × 4-cylinder triple-expansion reciprocating steam engine

2,750 ihp (2,050 kW)

Speed:
16 knots (29.6 km/h)

Range:
3,500 nautical miles (6,482 km) at 12 knots (22.2 km/h)

Complement:
90

Sensors and processing systems:

1 × Type 271 SW2C radar
1 × Type 144 sonar

Armament:

1 × 4 inch BL Mk.IX single gun

1 × 2-pounder. Mk.VIII single "pom-pom" AA gun
2 × 20 mm Oerlikon single
1 × Hedgehog A/S mortar
4 × Mk.II depth charge throwers

2 depth charge rails with 70 depth charges

Now a ship of similar size and form made with modern materials and techniques would have much more room inside (using diesel or turbine engines), much more capable systems and weapons, and would need fewer people to man and operate. Perhaps in the near future, that sort of hull could also be adapted as an unmanned vehicle as well for more dangerous jobs like minesweeping, task force piquet or air defense/missile defense platform.

jollyreaper said...

Here's a question. Marine and maritime relate to the oceans quite nicely. Navy comes from a french word meaning a fleet of ships and has a specific military connotation but naval architecture covers both military and civilian use.

So, if we are going to try to avoid the space is an ocean trope, what would be the appropriate suite of terms to replace it with? The natural choice would be "space" but it has zeerust connotations thanks to pulp scifi.

We currently have maritime law. I've heard the laws governing the use of space called space law but that feels less comic in a modern setting than a plausible mid-future one.

Aerospace feels a little too 20th century, as in aerospace engineering compared to naval architecture.

Generally I'm of a mind to not invent a bunch of made-up words for things we already know about, i.e. calling a rabbit a smeerp. But some changes can be good. Destroyer, Cruiser, Battleship, those words are already too freighted with meaning.

fro1797 said...

Ok, a Constillation for a group of military spacecraft. Space Cruiser for any spacecraft with the crew endurance and Delta-V for interplanetary missions. Monitor for heavy defensive ships; drone carriers,(comet/astroid) interceptors, (starship) desrtoyers, convoy escorts, response ships.

Ferrell

Geoffrey S H said...

Astral in instead of space?

navy= astraliate? astralate?

My setting has laserstars and kinetic carriers (smaller escort/mirror carrying laserstars) be referred to as 'dwarf laserrstars'.

A spacecraft with both lasers and missiles I refer to either as a battlestar or a fusilar (a portmanteau of 'battle' and 'rocket' in French- a 'battlerocket').

Craft with delta V for interception missions which are lighter than fusilars get called an 'interceptor-killer', or 'Intiller'.

Finally, for space freightors, I use the German for 'freight star'- 'handlestern'.

Thus:
Astralate.

Laserstar
Kinetic carrier
Fusilar
Intiller
Handlestern

Hopefully not too 'smeerpy'!

Thucydides said...

Not sure how the terminology would work, but perhaps the key factor in spacecraft mission design is the amount of deltaV that is available.

Ships with small amounts of deltaV would have very limited mission profiles (regardless of what they were carrying or their potential endurance, the ISS is a 700 ton raft because it's deltaV ability is essentially zero), while ships with large amounts of deltaV would have an enormous mission potential (even if the ship itself is the functional equivalent of a skateboard).

This is somewhat in line with other performance based distinctions used in the past (a Cruiser designated a ship capable of independent action over long ranges, and American fighter planes were designated "Pursuit" until after WWII (i.e the 'P" in P-38 "Lightning" = "Pursuit")

This may give rise to a series of numeric designations ("Captain, we have an enemy V3.1 closing on us"), but for people not versed in the system, this becomes confusing and distracting. Maybe this should be a qualifier on a ship description ("A V7.5 Laserstar is deploying its tracking mirror"), with larger numbers indicating higher performance and thus greater ability.

YMMV

jollyreaper said...

The setting I'm playing with now is trying to be a space opera friendly sort of thing. I'm slipping something in physics' drink and doing unspeakable things but at least the rules are self-consistent. Warp drives are used to move around but have to be outside of strong gravity wells. Antimatter rockets are used for moving in and out of wells and in combat. Smaller ships use sublight warp drives to move around in-system. Bigger ships have translight drives and can travel through interstellar space. Gravitational field interactions between stars create lines of effective warp transit and going off those lines makes for slow going. So while space is vast and infinite, useful routes are more constricted and thus create more opportunities for drama/interesting storytelling. With regards to the warp drives, smaller is usually faster.

Spacecraft -- incapable of interplanetary flight, usually carried by a larger vessel, your typical shuttle, lander, etc.

Spaceship -- capable of interplanetary flight, sublight warp drives

Starship -- capable of interstellar flight

Warship -- any vessel with combat as the primary goal

I like the ship type discussion from atomic rockets.

http://www.projectrho.com/public_html/rocket/spacewarship.php

As far as the setting goes, there's been a pretty big tech plateau once galactic-level tech has been achieved. The tech tree don't go no further. But developments in FTL have accumulated with increased speeds over the last few centuries. Colonies settled by ships that could do .9c at best are now in the backyard for neighbors with ships that can do much more than that. (50c? 100c? 500c? Still playing with the multiplier. And smaller ships can move more quickly.)

jollyreaper said...

So near as I can figure, you've got your Capital Ships, aka Large Size, fears no lesser ship, the only threat to a capital ship is another capital ship. I don't want to say battleship because of the bad historic precedents. I'd compare them to sharks. Sharks are the apex predator, nobody else can eat them but other sharks. They'll be battlestars. They can close and engage any target with their guns and anything too fast for them to catch will be chased down by their starfighter wing. The two general specializations you'll find among these capital ships are all guns or all fighters. The all gun models will be in the most heated fleet combats and planetary sieges. The carrier models rely on starfighters for all offense.

The primary weapon is essentially the turbolaser which does not offer the same potential knockout blow that modern antiship missiles or even WWII big guns could deliver. It's more analogous to cannons in the age of sail where size conferred an advantage to combatants but if you were too big and too slow you couldn't be of much use in battle.

The strongest polity in this setting essentially operates super battlestars because they are not just warships but mobile support bases and can operate independently for years at a time, capable of manufacturing any replacement part. The only thing it can't make are more crew. They're an entire battlefleet plus auxillaries in one hull, stupendously expensive, and built as such to Make a Point. They are prestige ships, much bragging rights follow with.

These capital ships are big and expensive to operate. They're not of much use in peacetime and are usually kept in reserves. These ships are balanced all-around combatants and don't really need escorts per se, they don't have the vulnerability to torpedo boats, submarines and aircraft that battleships shared. They can be overwhelmed by smaller opponents but will take many with them.

jollyreaper said...


Your medium-sized ships will do the interesting stuff in peacetime and wartime, the romantic frigates. The big dividing line between different medium-sized ships is endurance. Those that spend a lot of time deployed will need a far larger fraction of their mass devoted to habitability. Medium ships meant for defense within a single system might devote far more of the mass to weapons, armor and speed with the understanding that they would be miserable if used on longer deployments.

Small-sized ships would still be starships but very useful. FTL communication is not practical in this setting and so packet ships are necessary for communication. The only vessels that can threaten fast packets would be other fast packets or starfighters and their weapons are suitable for engaging either target. They usually can land on planets which increases flexibility. They're also excellent for scouting, raiding, and guerrilla tactics. They can hit where an enemy is weak and flee before a stronger force arrives.

Bigger than the capital ships would be battlestations which have a limited strategic mobility but garbage tactical mobility. As in, you take a system, you can move battlestations in to defend it but they are going to be sitting on top of the critical target and blast things that come close, they're in no condition to chase anything down. And if something too big for them to handle comes along, they're toast. There's no getting out of Dodge with them.

Other major mobile assets like battlestations will suffer similar weaknesses, even if they are armed to the teeth. They represent possessions too important to risk in combat. Expensive as they are, you are prepared to lose capital ships. An orbital with ten million onboard, it may be armed but you are doing everything in your power to keep it out of the fight. It's impossible to make an object like that armored for combat and useful for anything else.

I'm still using placeholder names on these classes because I don't want to reuse old conventions loaded with assumptions but I want to avoid smeerp territory.

So as far as getting away from explicitly nautical, I'm thinking...
mariner = starfarer
sailor = crewman (spaceman has been zeerusted to death)
astronaut/cosmonaut/taikonaut = still starfarer or crewman. It doesn't feel right putting those words in this setting
navy = space force
fleet = fleet

The funny thing is the story I have in mind won't touch on but a tiny fraction of the details here but it's like an alligator lurking under the water: knowing the shape of the rest of the beast shows where the eyes and nostrils should be poking up.

Eth said...

Astral is interesting. "Astre" in French means "celestial body", and is found in Astrophysics or Astronautics.
Btw, Astronautics is what you get when you take Aerospace and you remove the Aeronautics part - may be useful for your space-only crafts.
Navy is based on an old French word, who gave "Navire" in modern French, meaning "(Naval) Ship". The modern French word is for Navy is "Marine". The English word Marine is from "Marin" ("Seaman"). For this, we already have Espatier, that I would keep.

"Marine" also being the (feminine) adjective for sea-related stuff, the equivalent would be Astrale.
I quite like it, actually. It sounds pretty good in French to me, at least.

I would avoid portmanteau, though. They are pretty rare and don't really work in French.

I personally like Constellation for a myriad of coordinated ships, particularly drones. It's already in use for satellites, it doesn't take much to apply it to operating fighters/drones.

Btw, are your fighters Star Wars fighters, or more like small 1-person corvettes? For the latter, I would suggest Vedette. It has mostly naval connotation in French, but less in English AFAICT. (Funnily, it also mean "Star (of a show/event)" )
Also, are there drones in this setting?

For capital ships, the all-guns ones are pretty much battleships. The French word for Battleship is "Cuirassé" (lit. Armoured - from Armoured ship). Close-sounding, there is Cuirassier that I like. Some may not like the heavy cavalry reference, though.
Otherwise, while there is no exact translation for Capital Ship, I personally use "Bâtiment de guerre", which means "(Big/major) warship". Interestingly, "Bâtiment" also means "Building" in its more common context.
So you could go for Batiment for capital ships (don't worry about the accent).
Superbatiment for the prestige ones would work, I think.

The word for aircraft carrier is "Porte-avions" (porter meaning to take/bring/carry). I've seen Porte-vaisseau ([star]ship carrier) used in SF, and that's probably the best way to translate a Spaceship carrier.
Starcraft translation used "Porte-nef", which was inaccurate (those were drones) but sounded pretty badass.
So a drone carrier would be a Porte-drones
Though simply keeping Carrier would make sense IMHO.

"Vaisseau" literally means "Vessel", but is the word used for Ship as in "Spaceship" (literally "Vaisseau spatial"). May be useful, I don't know.
I've seen a few translations use "Nef" for big, long-range starships. A "Nef" is an ancient, large ship, but is also the central part in a church (probably because of the shape). I personally like how it sounds, so maybe useful too.

Eth said...

Long-range independent ships are Cruiseurs ("Croiseurs"), for the same reason that in English, "to Cruise", "Croiser" - though in French, it's specifically a military navy term basically meaning an hunting/interdiction patrol.
IMHO, the term is similarly fitting well the military reality of your setting.
So I would keep Cruiser despite the maritime connotations, because cruising is what they do.

Right now, I don't see any obvious name for a medium defence ship. It would be Corvette, but that's heavily naval-connoted, like Frigate ("Frégate").
The French Navy use "Aviso" as a sub-corvette ship class, so there's that. The name actually comes from the Spanish "Barca de aviso", meaning "Notice/warning rowboat" if Wordreference is to be trusted (which sounds right, "Barca" is close to "Barque" - "Rowboat", and "Aviso" to "Avis" - "Notice").
Or you could use the previous Vedette, as it also has a guard context (more in the warning sense, but it should still hold IMHO).

For packet ship, that would be "Courrier", so there is already Courier for it.
For ships designed to intercept them (and other fast targets), I would stick to Interceptor ("Intercepteur"). Like for cruisers, that's what they do.

Right now, I don't have any obvious choice for a raider ship. Raider doesn't have an obvious translation, and is sometimes used as an anglicism. There is "Pillard" specifically for bandits or barbarians that are attacking you and ruining your stuff to steal your things. An infantry raider team would be a "Commando" (means the team for any such action, and the single individual only for a military operative). "Raid aérien" is used in French for air raid, and "raid" is used in a few non-violent contexts.
So I would stick to Raider, and Infiltrator for its more discreet counterpart for now.

Similarly, for battlestations, I don't see much of an equivalent. French already use "Station spatiale" for space station after all.
OTOH, I don't find any formal definition in English either, apart from a "General quarters" synonym (in which case it would be "Poste de combat"(modern) or "Branle-bas de combat"(old/figurative), but that's not useful right now).
So I would either stick to Battlestation or go for War/military station, Mobile base/fort/fortress or any such term.

I like Starfarer, good one!

Did I forget anything?

Thucydides said...

Trying to remember the old Traveller RPG, which had some interesting designations.

Small warships without star drives were known as System Defense Boats, and were roughly analogous to a torpedo boat or guided missile corvette. Because they did not have the mass or bulk of a stardrive, these were much more powerful than a similarly sized starship.

Most of the usual tropes (frigate, cruiser and battleship) carried over, but they could also be subdivided into the self propelled ships (analogous to cruisers in the steamship age) or "Battle Riders" which dispensed with stardrives in order to generate a much bigger punch. They were attached to a massive "carrier", which was actually more of a framework carrying the stardrive. You could imagine it a as huge mobile dock carrying an entire squadron or division of warships.

Traveller was generally not too keen on fighters, although they included them as a sop to gamers who would not let the trope go. Readers of Atomic Rockets can study the gory details at that site.

Once again YMMV

Eth said...

About Starfarer

I would suggest have two different words for those who work on interstellar ships and those who stay in one system, like the difference between Starship and Spaceship

Starfarer would be the former, and Spacer would work for the latter. It's used in other SF works, but IMHO it zeerusted like Spaceman did (yet).

(In French, there is a similar distinction between "Marin", "[Seawater] seaman" and "Marinier", "[Freshwater] mariner", but I don't know of an equivalent in English, as Mariner is used for seawater crew as well AFAICT.)

For the military, I would be for Astronaut. Sure, it has an US connotation, but having separate words for US Astronaut, Soviet/Russian Cosmonaut, Chinese Taïkonaut (though Chinese official papers written in English use Astronaut), French Spationaut (rare nowadays though - now Astronaut is used as in the rest of ESA), Malay Angkasawan and Indian Vyomanaut (still speculative, though)... well, it kind of makes no sense. And originates from a false-friend mistranslation of the Russian word.
And as most countries now use Astronaut as the default word (because more countries primarily work with NASA than with Roscosmos, I suppose - though again, see the Chinese), I'd say it kind of won the word race by default in the end. Sure, nowadays it has less of a military ring as there are proportionally civilians among them, but it still keeps a State program feel, which is close enough.
It also has the advantage to be gender-insensitive, something some people may find handy.

And if you go with Astrale, then Astronaut it's the most logical word to go with it; "Astroman" being out of the question.

Eth said...

Thucydides:

I like Battle Rider (could be shortened to Rider). It's functional, recognizable and sounds good. It also evokes speed/agility and being light (horses or bikes compared to cars and bigger vehicles), which would work well for fighters or other carrier-borne light attack ships.

For SDB, the problem is the "Boat" part, which is very much water-connoted. Though it could be replaced by "ship", to get SDS
Also, "boat" feels smaller than "ship", while they could be bigger than small- or even some medium-sized ships.
Orbital defence could similarly be SDC for "craft".

I would personally try to avoid acronyms for ship types when possible, but that's more of a matter of taste.

jollyreaper said...

Eth,

Astral might be sufficient. Astral Law, Astral Courts. For Astrale, is the E pronounced? Is it ass-tra-lay?

Constellation still feels too static for me, especially since current use is for satellites that aren't going anywhere. Could just be my own bias here.

I'm trying to avoid directly translating English class names into foreign languages since it just perpetuates the existing problem.

I might be able to keep cruiser since it is such a generalized name. We have bike cruisers, police cruisers, cruise ships, etc.

As for the setting, I'm trying to go back to the sources Star Wars and and later imitators mined and build a setting that has a feeling of verisimilitude without obvious logic holes while still keeping the fun.

The thumbnail history of the galaxy is that there have been four or five pre-human interstellar civilizations but they've all died back. Aliens are still around, sentient ones at that, but anything leftover from the prior civs are fallen survivors. Human civilization originated in a cluster of homeworlds and sent out several waves of colonization ships which in turn founded colonies that sent out ships of their own. You have robots (unthinking machines), mechanoids (thinking machines) and bioroids (genetically engineered lifeforms) as well as people who have a legal claim to being human but, with genetic drift and engineering and thousands of years of separation, can all look rather different. I'm avoiding dumb bumpy forehead aliens, there's got to be a reason for the drift. I can't imagine anyone thinking the Klingon look is desirable.

Throughout most of this history star systems were relatively autonomous. It took ages to get anywhere, you had to be self-sufficient when you got there, there's no galactic economy, no trade.

Wars, always having an ideological component, were poor for libraries with inconvenient facts. It became difficult to keep information protected and sufficient scrambling of public records could even cast preserved private copies in a suspicious light.

The thing that keeps happening is civilizations will rise and fall and never break the tech plateau represented by the technology the colony ships went out with.

The development of faster warp drives and limited FTL coms from system to system has suddenly shrunk the galaxy a great deal.

All of the colonies have a reverence for the motherworlds though few have any idea what that truly means. You'll have blue-skinned humans declaring themselves the genetically pure descendants of the homeworlds and green-skinned humans calling that a lie.

The motherworld civilizations are a step more advanced than everyone else and jealously guard the advantage. They also have become concerned about the rise and fall of civilizations. When everyone was isolated, a rise and fall was contained. With a growing galactic economy, the entire human sphere could go out together. The homeworlders decide that all of humanity must be civilized or else face extinction. It's bad logic but believable bad logic.

The effort to bring everyone into doctrinal alignment ends up ruffling a great many feathers. Hence the premise of the big war.

jollyreaper said...

As for the tech, I'm keeping it simple. Antimatter is the basis of the interstellar economy. Without it you don't have FTL ships, no fusion reactors (can't get the oomph started without antimatter to kick it off and sustain it), no super-heavy artificial elements. the super-heavies are the magic sauce for all the unobtanium in the setting. You need giant stations near stellar objects to create the antimatter. This means stars are the most important high ground in a system. Gas giants with their strong magnetic fields are weak secondary sources. Planets are prestige possessions and people like living on them.

Mechanical minds are housed in crystalline neural nets. They need to be trained just like live minds, cannot be copied or uploaded. The cheaper ones are capable but not inventive. Very capable minds aren't in mobile robotic bodies but are warehouse-sized affairs and loathe to experience the dangers of going places. There's also a hard limit to thought in this setting, you can't get really transhuman in thinking power. It leads to instability. The thinking machines can't get much more powerful than humans and don't scale well. They are also vulnerable to handwave radiation thrown out by small ship reactors. You need to get on a medium-sized ship before they can afford the kind of shielding that will keep a mechanoid mind from going loopy. (I'm thinking of handwaving neutrinos. The crystal quantum mechanics going on in their brains is the only sort of thing nuetrinos can interact with. Humans are unharmed.) Human beings represent the best thinking substrate available for cost and mass that's also crazy enough to risk destruction doing adventuring things.

Obviously, this is a bunch of fudging to keep humans relevant. Glorious space opera can't make any kind of hard SF sense.

Eth said...

That's an interesting setting, I'll be curious to see how it grows and what you do with it.

They also have become concerned about the rise and fall of civilizations. When everyone was isolated, a rise and fall was contained. With a growing galactic economy, the entire human sphere could go out together.

That's actually something that's nagging me for a few years now, about our increasingly connected and globalized economy. As it resonates with possible problems of today (and tomorrow), it makes for good, interesting SF material.

And I suppose they don't have autonomous unthinking drones because it's not cost-effective to get them secure, hacking-proof and reliable enough, so they're stuck with romantic, trope-filled exciting space fighters instead, those poor souls.
Are those space fighters more like a Star Wars TIE or a Star Trek (warp-less) Runabout?

For Astrale, is the E pronounced? Is it ass-tra-lay?

The E isn't pronounced, like in "Marine", so it's pronounced like "Astral": ass-tral
Like Marine, it's feminine, I suppose because Army and Force are feminine. I suspect that it's a shortened version of "Marine force" (the adjective becoming a noun) or an equivalent but couldn't find the etymology.

Constellation still feels too static for me, especially since current use is for satellites that aren't going anywhere. Could just be my own bias here.

Yeah, I can see your point. I feel it having drone connotations with its trajectory carefully planned by a collective system, so if you go drone-less, I'd also avoid it.

Eth said...

I'm trying to avoid directly translating English class names into foreign languages since it just perpetuates the existing problem.

Ah, I understand.
The difficulty is that quite a few of those names have a logical origin based on their function or nature. So for hardware with the same role, we will end up getting the same names. In the case of Cruiser, it became general enough, but others are harder because we don't see them much beyond naval elements.
Battleships are the ships made for battle, those that are the most efficient at exchanging fire with enemy assets.
Similarly, Cuirassés are the ships that have been heavily armoured, the distinguishing element of those capital ships at this time.
Carriers are the ships that carry other ships.
(X) Destroyers are the ships that are specialized in countering X. Here, it could be logical to call specialized anti-fighter ships Destroyers, for example, for Light Ship Destroyer. The equivalent of today's AA frigates.

For example, for battleships, you could also Cannoneer. But "Canonnière" already exists, meaning Gunboat.
In fact, as Canonnières were pretty different from those battleships, it could make things even more confusing.

Frigate and Corvette, on the other hand, have etymology specifically linked to their nature as boats and elements composing them - even though those elements had long been forgotten even centuries ago.
So you could also try to go this way: take a role and identify the particularities of ships commonly fulfilling this role, either current or from the past.

Maybe capital ships use(d) big magnetic nozzles, with a spherical grid around it to maintain the magnetic field. So they would be called Lanterns (coined on this blog IIRC). Even if tech evolves later to make Lantern drives obsolete, the name could have stuck for capital ships.
Maybe aerospace-capable medium ships similarly use(d) very loud and recognizable growling air engines when in the high atmosphere, getting them called Gronders ("Grondeur" would mean "Rumbler", but mostly I like the sound of it, if feels pretty nasty in English - the reference to LotR's Grond may or may not be purely fortuitous).

Random other ideas:
Jouster - a ship that is dancing around, trying to get close, stab you in the bridge and continue its way before you can stab it back. Jouster duels tend to be brief moments of exciting brutality separated by longer manoeuvring if both got lucky enough on the first round.
Lancer - a ship that has one big nasty energy lance as main armament and that just want to stab you from bridge to engine with it. Probably not that manoeuvrable, but not a sitting duck either.
Dragoon - originally soldiers who had firearms that breathed fire like dragons, or dragon-gunners in a way. Later became infantry capable of riding (mounted infantry, a concept I always had difficulty with tbh), then lots of things from tanks to NBC troops and special forces... The point is, dragons are awesome, and dragoon already has a history of military use so maybe it could fit a starship. Probably a relatively light but well-armed one, maybe a raider.

Anyway, as long as you don't bring Battlecruisers back for the capital ships :)
Though I had got this idea for another setting where Battlecruisers would be Cruisers hastily re-purposed as stop-gap battleships by cutting their endurance and slapping some more guns and defences.
Like in real-life, they would be a bad idea if you can avoid it, and tend to messily explode instead of being the Cruiser-but-even-more-awesome!! that we see around.

fro1797 said...

Monitors were large, heavily armed ships that were used for coastal defense, so calling a planatary defense ship a Monitor might make sense. A response ship might have a huge propulsion module, a small command module, and a swappable mission module. Escort, Destroyer, Interceptor all make enough sense that those term might be kept. Drone Carrier also is self-explanitory. The trouble with inventing the name of a ship class that describes the largest, most powerful ovecombat spacecraft, is that the names of sea-going capital class warships evolved over time and related to their primary attributes. For example, a 22nd century "Space Fighter" might mean any combat spacecraft with a single crew shift, and a crew endurance of less than a week, dispite their armament or mass.
"Constillation" might only mean a Drone Carrier when it's drones are deployed. I'm not sure what the name of a large ship that acts as a mobile base for a squadron of Battle Riders would be.
A ship that is armed with a huge laser, multiple smaller beam weapons, missiles, rail guns, drones, and various other weapons (like Nuclear Detonation Lasers, Nuclear Shaped Charges, or even more exotic arms), heavy armor, a massive electronic warfare suite, and enough command and control capability to direct a fleet would be a capital ship, but what to call it? A Storm Ship? ("...If that thing makes it into orbit, it'll bring a storm of fire and metal to our world!") It might depend on if it evolved from an Astroid Deflector ship, or a Planetary Defense Ship, as to what it's called. It might just get it's name from a prominate feature on the original vessel of the type. Whatever it's called, it should be logial and unique.

Ferrell

Thucydides said...
This comment has been removed by the author.
Thucydides said...

Actually a "Lantern" (Lanterna) was a term used near the end of the age of war galleys to designate a large and exceptionally heavily armed galley. The designation was from the large lantern humg from the stern of the ship to identify it.

A "Captain" (Capitana) was a similar designation for war galleys, indicating the ship the senior commander was on (considering the Captain was often an independent contractor, there could be multiple Capitanas in the fleet)

It is interesting to look at the list of the Christian ships in the Battle of Lepanto and see where the Capitanas and Lanternas were posted.

Reference:
Guilmartin, John F. (2003). Galleons and Galleys: Gunpowder and the Changing Face of Warfare at Sea, 1300-1650. Cassell. ISBN 0-304-35263-2.

(reposted due to editing issues)

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