Comments on Rocketpunk Manifesto: Further Battles of the Spherical War Cows

Pressure certainly poses a problem. Maybe a better...

2011-10-15T11:54:01.612-07:00

Pressure certainly poses a problem. Maybe a better system would be to have transparent pipes with an opaque liquid pumped through them. A relief valve can divert liquid to storage to prevent to much pressure from building up and a cooling system can remove the heat.

Gareth.

Welcome to the comment threads! Alas, I think a t...

2011-10-14T19:47:41.371-07:00

Welcome to the comment threads!

Alas, I think a transparent layer would backfire - the vaporized material under it would be trapped, and build up to explosive pressures.

It might not actually be worse, but not any better either.

Has anyone ever considered putting a layer of tran...

2011-10-13T08:56:42.091-07:00

Has anyone ever considered putting a layer of transparent material over the armour? This would prevent outgassing from the hole and force the laser to heat the remaining armour indirectly.

Gareth

Thanks, I'll shut my yap until I've gotten...

2011-04-16T21:05:13.479-07:00

Thanks, I'll shut my yap until I've gotten caught up!

Welcome to the comment threads! Comments on older ...

2011-04-14T20:57:25.694-07:00

Welcome to the comment threads! Comments on older posts are fine. (Though there's the risk that I'll miss it - I get email notifications, but comment traffic has been getting wild lately.)

I've pretty much abandoned the idea of a cloud of debris as an effective kinetic punch, largely for the reason you hit on: the laserstar only has to target the fragments on intercept course. Which are easy to identify. Target seeking submunitions appear to be the main kinetic threat.

My guess is that simultaneous multi-axis kinetic attacks will be very hard to set up - the target may not be able to evade them outright, but can move to encounter one before the other.

The comment threads on recent posts - especially Space Warfare XIII: The Human Factor - have a LOT more discussion (and disagreement!) about laserstars versus kinetics.

Hello, I hope it's not bad form to comment on ...

2011-04-14T18:39:24.161-07:00

Hello, I hope it's not bad form to comment on an old post. I've just stumbled over your blog and have been reading my way through.

I was wondering if there was a flaw in the tactic of the fragmenting kinetic bus vs laserstar. The bus breaks up after its armor is burned through, saturating an area too large for the laserstar to avoid and too numerous/heat absorbent to vaporize completely.

But the laserstar doesn't need to zap all the fragments, just vaporize all the buckshot in a hole big enough to fly through, plus some margin of error. If it has trouble spotting the shot, it can just scan its beam around in the area of concern and look for puffs of ionized vapor (or use IR sensors to spot the now heated fragments), then focus there until there's no more vaporizing and move on.

Things get more complex with multiple buses coming from different angles, since you'd have to figure out where you need the gap to be in each wave and at what time, taking in to account any maneuvering you want to do before the waves arrive.

Now if the shot itself is somewhat mobile, this gets trickier, but my understanding was that it was just a cloud of flak after the bus breaks up.

With a torchship, I see turrets as being practical...

2010-04-13T07:00:38.409-07:00

With a torchship, I see turrets as being practical. If your opponent can move quickly, then it makes sense to be able to track without turning the whole ship. Weapon dynamics will be driven by a lot of things, including engine technologies.
Actually, in a torchship setting, I see orbit matching and such as much more common. This is because of the prevalence of "everybody dies" combat options, which nobody wants, such as kenetic-firing passes. I would think that war is governed by a set of unwritten rules, that ensure that combat mostly occurs at low inital relative velocities. Not formal "we'll send our champion, you send yours" rules, but just that combat will be usually decided in matching high orbits.

I'll guess that the duration of combat is shor...

2010-04-12T19:01:57.462-07:00

I'll guess that the duration of combat is short enough (no more than hours) that you can unshutter your mirror, and natural impact damage will be a fairly minor concern. In any case, in combat you have to point it toward the enemy, whether or not that also exposes you to debris.

And yes, I'm mainly assuming Realistic [TM] deep space drives with milligee thrust, for which maneuver on the combat time scale is also pretty irrelevant. So you can put the ship in whatever attitude is needed to put the mirror on target.

If you have a torch drive, you have a different set of design constraints.

Byron said... " But what is forward? The t...

2010-04-12T12:21:04.284-07:00

Byron said...
" But what is forward? The thrust axis is the most likely answer,"
Yep. For "forward" I meant "thrust axis while accelerating" (and also afterwards with the nose pointed in the same general direction as the speed while coasting).

Since Rick and all of you are mostly talking of low thrust (but high Isp) drives, the ship has a pityful acceleration. This means that it must spend a lot of time accelerating with the nose pointed in the direction where dust or other particles can damage the mirror.

During a cruise this is not a problem, the mirror can be shuttered (unless it is insanely big), but during a fight this becomes a bad thing.
Or at least I think it could.

Torchships have no such problems, due to high acceleration. You can keep the mirror shutterd for the few seconds of jinking burn and then rotate the ship around like a flying pistol when shooting.

-Albert

But what is forward? The thrust axis is the most ...

2010-04-06T19:35:27.864-07:00

But what is forward? The thrust axis is the most likely answer, but "broadside" weapons are not really that different, except as being bad as pursuit weapons. Then again, it might be a good idea to build a ship with a high roll rate, heavy armor on one side, and a big mirror on the other.

This becomes more complicated if you want a big mi...

2010-04-03T10:43:27.054-07:00

This becomes more complicated if you want a big mirror, and if your laser is in the IR-visible-UV band you probably do. I suspect that these big mirrors will have to be keel mounted, though they might point either forward or to one side.

An interesting idea, but with a rather large probl...

2010-04-03T07:36:21.292-07:00

An interesting idea, but with a rather large problem. Ships don't have to fly facing forward. In all reality, with sufficiently powerful drives (torch drives) it would actually make sense to point your engine at incoming kinetics and burn them out. Still, there is no "straight ahead," so it would make more sense to just turn the nose away.

huh. I read somewhere in this or the other blog po...

2010-03-30T12:39:00.516-07:00

huh. I read somewhere in this or the other blog post on Battles of Spherical War Cows that laser optics and mirrors are highly susceptible to kinetic damage from dust or even small particles from the vaopour of zapped kinetic impactors.
I mostly agree, but I have some (rather naive) thoughts on it.

When reading Atomic Rockets, i read about that Boeing aircraft with a laser turret on the nose.
They say it never shoots directly forward, because dirt or flying insects (or even birds, for that matter) could smash on the optics damaging them.
Looks the same problem.

What if the laser mirror is placed on the side of the ship (like a cannon on a galleon in the old days) and only shoots "Zap broadsides"? (i.e. the mirror would be in some kind of sponson, not fixed to the hull to allow targeting)

This way the optics and the mirror itself are protected from spaceborne dust and the tiny pieces of kinetic impactors vapourized (a laughable threat for the ship, but supposed to be deadly for the mirror).

This layout forces the ships to carry much more armor (they must have their sides armored too if they want to shoot before getting sliced).

And also restricts the field of fire, the laser would now be unable to target things right ahead.

Oh well, it may open a can of worms or just be a crazy idea.
Galleons IN SPAAACE!!!!!
What do you think?

-Albert

Welcome to a couple of new commenters! I'm no...

2010-03-29T10:20:53.147-07:00

Welcome to a couple of new commenters!

I'm not entirely surprised that X ray lasers are making their debut. There are still challenges, since conventional optics don't work at all, so you can avoid them in a story setting if you don't want them. But if you do want them, this makes the case that much stronger.

Microwaves seem just not concentrated enough for most weapon roles, but I could easily be wrong.

The weakest spot of kinetics is always guidance control, because cripple, blind, or even just dazzle it and it will probably miss. Diffuse clouds might well be effective, but I suspect that point defense lasers are favored, because they direct all their energy at the actual targets, not wasting any on the space between them.

There are actually several different ways to make ...

2010-03-28T12:26:34.355-07:00

There are actually several different ways to make a microwave weapon. Besides the above-mentioned maser, which is unsuitable for weaponization due to power levels, there is a device called a vircator, or virtual cathode oscillator. It produces narrow-band microwaves at gigawatt power levels. It's not coherent, and it's not really useful for direct destruction, but you could use it to damage electronics. Lastly, an FEL would also work to produce microwaves.
Also, wouldn't a diffuse particle cloud be useful for defense against KE weapons, at least small ones. I imagine that the SCODs would have a hard time steering with portions of the shield vaporized, and sensor damage might result.

looks like X-ray lasers are a reality... http://...

2010-03-25T13:31:59.162-07:00

looks like X-ray lasers are a reality...

http://www.physorg.com/news159556347.html

Are you ready for them?

-Albert

New Anon - welcome to the discussion boards! Frag...

2010-03-01T09:41:07.579-08:00

New Anon - welcome to the discussion boards!

Fragmentation weapons is how I originally conceived of kinetics, on just the principle you suggest. But when I 'played out' the engagement between laser defense and incoming kinetics, there wasn't much advantage to fragmentation unless the individual kinetics are quite big and heavy.

But overall the best kinetics are the smallest ones that will do damage, and can be fitted with terminal guidance. And given current trends, I'd already expect guidance packages to be (relatively) small and cheap - in effect, smart bullets, rather than a shotgun blast.

If you wanted to be mean about it, couldn't yo...

2010-02-27T17:06:15.966-08:00

If you wanted to be mean about it, couldn't you start off with say a 750kg projectile, make them burn through the armour, then just before it goes, explode it into hundreds of 1kg projectiles, which just before being disabled, again become hundreds of 1g projectiles? Etc.

My knowledge on masers is pretty recent. I was try...

2009-10-15T21:29:45.001-07:00

My knowledge on masers is pretty recent. I was trying to figure out a way around our fragile mirrors and was starting to think about phased arrays (like the Aegis radar) to come up with something less vulnerable. To my dismay the limitations on masers shot that idea out of the water... out of space pretty quickly. I'm not sure if the optical interferometry technology used in the ESA's VLT array is applicable to laser optics, but since even those use 8m mirrors, it's not very helpful even if it was.

Back to ye olde drawing board.

Thanks for the notes on masers - I didn't real...

2009-10-15T18:29:28.385-07:00

Thanks for the notes on masers - I didn't realize that they were contained entirely inside the resonant cavity. I did know that the long wavelength was (to say the least) unhelpful for energy concentration.

Keeping the Fresnel lens exactly aligned might not be such a problem (in principle!), if you're defending a specific point target - such as your own laser mirror. The lens doesn't need to be a long distance in front of the target it protects; a few hundred meters would be fine.

There's still the problem of the beam melting the lens - but the lens doesn't need to be precision optics, and even as it bubbles to extinction it will still distort the beam passing through it. :-)

Which still leaves a fair number of problems with the idea!

Oh, and masers as we build them aren't really ...

2009-10-15T13:14:32.113-07:00

Oh, and masers as we build them aren't really applicable as beam weapons as they employ resonant feedback inside a microwave cavity, and we don't actually know how to build them into radiant beam devices. The power levels of masers as they stand today are also laughably in the picowatts, when we can build large solid state lasers that can reach into the megawatts. This is due to the fact that microwaves are very low energy wavelengths.

My question as to microwave lasers as weapons was rather rhetorical since right now we don't even know what one would look like.

Well, the problem with the Fresnel lens is a/ you ...

2009-10-15T13:03:06.049-07:00

Well, the problem with the Fresnel lens is a/ you somehow have to place the lens *exactly* between you and the guy shooting you, and b/ like a mirror, the energy of the beam will ablate the lens and eventually destroy it.

Also, if we *can* actually create self-sustaining plasmoids, wouldn't that be like a Plasma Cannon used in defensive mode? Oh noes, a plasma cannon...

I didn't say it was Plausible, merely suggested it was Possible. Practical is way over on another planet.

There are definitely microwave laser equivalents: ...

2009-10-15T07:55:42.943-07:00

There are definitely microwave laser equivalents: - masers, which in fact were developed some time before lasers were. When lasers first appeared they were sometimes called 'optical masers.'

(Alas) I can't really see any practical, non-magical way to deflect/defocus laser beams. The closest I can come is some way to generate ball lightning, a plasmoid that would be self-sustaining, and could be maintained in the path of a hostile beam to distort it.

But a better way to get that effect might be a drone with a big Fresnel lens, or some such.

Babylon Freak "Laser defense system: possible...

2009-10-14T20:56:50.541-07:00

Babylon Freak "Laser defense system: possible.
Cloaking device: not."

Which is pretty much what I am trying to say about a cloaking field-inspired laser defense system.

As for the tunable laser frequency to the defense system, well the earlier generations of this defense system would not be completely possible or even efficiently possible. Which would mean that the system would either have a set blocking frequency or multiple modules with different frequency against certain laser types. Tunable laser defenses would more likely be a gradual and future development of such a defense system.

As for the technical part in the creation of such a laser defense system: I got nothing but I am open to any suggestions as to how this might be possible, scientifically plausible or not.

- Sabersonic
Sabersonic@hotmail.com
jrposadas@gmail.com

Yes, but, which part of the spectrum, and how fine...

2009-10-14T20:05:20.550-07:00

Yes, but, which part of the spectrum, and how fine-tuned, and/or tunable? Who says your opponents use lasers of the same spectral class as your own? Who says all your lasers are precisely calibrated to the same wavelength, either due to a different batch of lasing material to a deliberate attempt to make this defense impossible? Not to mention that actually infrared lasers are the easiest to build and obtain high power from. Microwave "lasers" (are there such things?) would be vastly underpowered compared to IR lasers. Once again, a plasma window needs to be inside a containment field, requiring field generation devices to be on the wrong side of the shield. I am not saying those are impossible issues to solve, but something to think about when you create your laser defense/deflection system.

So, the laser deflection system *could* be possible. It still doesn't solve the cloaking aspect. Either:

1/ the EM-warping field can deflect IR, in which case you get cooked by your own heat.

2/ the EM-warping field does not deflect IR, in which case your enemies detect your IR signature.

Laser defense system: possible.
Cloaking device: not.