Monday, September 23, 2013

Vandenberg Spaceport


I'm baaaaack!

Yes, the hiatus has been far too long - I kept thinking 'just another day or two,' after a move, working on Catherine of Lyonesse, an annoying and voltage-draining sinus infection, and, well, work.

The move means a regretful farewell to the F line streetcars, 100,000-ton containerships, and more places to eat than we could ever possibly try. On the other hand, the Central Coast does have a justified reputation as a corner of paradise.

Of more interest to most readers here, the move puts me back within decent viewing distance of launches from Vandenberg Air Force Base.

Alas, relentless California coastal summer fog rendered the late-August launch of a Delta IV Heavy invisible. As the seasons turn, bringing Indian summer to the coast, I have better hopes for the upcoming Falcon 9 launch, postponed from midmonth and now scheduled for September 29th.

For those who live near the West Coast, or simply want to keep track of launch schedules, here is a Web page listing scheduled Vandenberg launches.

This launch schedule also provides some important - and frustrating - lessons about the practicalities of space flight.

The most important of these lessons is that space launches are rare. Not counting ICBM test flights (one pending, and one I slept through and missed a couple of nights ago), three launches are scheduled between now and March. Throw in the late-August Delta IV launch and it comes to four launches over an eight-month period.

This is surely not an 'efficient' usage of facilities and resources. A space launch center must be broadly comparable to a large airport. The vehicles it handles are about the same size as jetliners, and at least as demanding. They must be prepped, serviced, and sent on their way, using a lot of specialized equipment, and - even more expensive - teams of human expertise.

If a major airport handled one flight every other month ... airline tickets would not be cheap.

In fairness, Vandenberg is not the most heavily used launch center. It is used for polar-orbit launches, particularly for spy satellites, though also for some types of geosats for which maximum coverage of the Earth's surface is important. Polar-orbit launches cannot benefit significantly from Earth's rotation, so they are avoided unless specifically called for.

But sometimes they are called for, meaning that all traffic cannot be consolidated to a single launch site. Worldwide there have been rather less than 100 launches in each of the last few years -74 in 2010, 84 in 2011, 78 last year, and 52 so far this year.

This includes a handful of failures each year; out of 286 attempts this decade, 18 were failures, a 6 percent failure rate. This is, I believe, a somewhat higher failure rate than in the last couple of decades - at least in part, I'd guess, because of more new and inexperienced players in the game.

But any way you cut it, space launches are not an everyday event - more like one or two per week, worldwide.

The problem of low traffic volume does not just drive up the cost of launching rockets. Production of any one given type is only a dozen or so per year - up to 19, in 2011 for the Russian workhorse Soyuz (R-7) and China's Chang Zheng. Individual Western booster types rarely see more than half a dozen launches per year. Forget production-line efficiencies.

This traffic volume also puts paid to reusable launch vehicles. Quite apart from technical challenges, there just isn't the traffic to keep them busy. (And since payloads vary widely, you'd really need a stable of types, just as with expendables.)

In fact, given the traffic level, a stable of expendables is the most cost-effective approach. For any given individual payload they are far less expensive than a reusable vehicle that has to not only get the payload up, but then get itself back down.

Yes, this is a dead horse I have beaten here many times before, and will no doubt beat again. But actually living where I can watch space launches brings some immediacy to the topic.

On the bright side, we are sending some 80-odd missions a year into orbit and beyond. More than that, in fact, since many launches carry multiple satellites. As also noted here before, we have sent missions to every major planet in the Solar System, and a good many other objects.

And I am looking forward to Sunday morning, when that Falcon 9 is scheduled to go up. With a little bit of luck the sky will be clear.

Discuss:





The image, via Flickr, shows a Delta IV Medium launch from Vandenberg, last year.

450 comments:

1 – 200 of 450   Newer›   Newest»
Anonymous said...

Just in time to comment on this post, I forgot where I left the BBC article about Japan's new AI equipped rocket that reduces launch crew from hundreds to eight.

And it's my first time commenting on this blog after two years of lurking. Whee!

Damien Sullivan said...

http://www.bbc.co.uk/news/world-asia-24090322 for Japan's Epsilon rocket.

Somewhere out there is a web article by someone arguing the gov't should commit to daily launches, to bring the price down and see what happens. IIRC.

Damien Sullivan said...

Damn it, knew I forgot something.

That was one thing that impressed me about Gattaca. All this genetic dystopia focus, and in the background are weekly rocket launches for some manned expedition to Saturn and who knows what else.

JIm Baerg said...

Maybe the worlds launches should be consolidated to the site in French Guiana, which has open ocean to both the east & north, making this one launch site good for any orbital inclination. Would the ESA be OK with SpaceX using that site? This idea is probably too sensible for the real world.

Damien: I think this is what you recalled http://www.fourmilab.ch/documents/rocketaday.html

Rob said...

ESA could probably be brought around to the idea of having F9's launch out of French Guiana. The problem is actually whether or not the USG would be willing to let US rocket technology be exported for the purposes of launching from French Guiana.

Brett said...

So is the bulk of the launch costs in the ground work, and not the rockets? I remember Tony saying that at one point, in a post years back.

In any case, it sounds like a good argument for in-orbit re-fueling of satellites and spacecraft. You could use the cheapest rockets you have that will work, and do a continuous launch schedule consisting mostly of launching kerosene fuel and oxygen up into LEO to be used on various sundry spacecraft once you get the hang of the "re-fueling" technology and infrastructure. You might be able to draw oxygen from the upper atmosphere later on and just send up kerosene, but that's farther down the road.

That would at least keep a busy launch schedule in the spaceport, spreading out the costs per launch of keeping all the support staff on site. . . . assuming it paid for itself on net, which is always the devil in the details.

I think Zubrin had an idea along those lines in a speech a while back. Subsidize a bunch of flights to the tune of ~$1 billion a year, and for the flights that aren't carrying scientific/commercial/whatever payloads, send up fuel tanks to orbit around in LEO until somebody can use them (or they fall back into the atmosphere and burn up).

On the bright side, we are sending some 80-odd missions a year into orbit and beyond. More than that, in fact, since many launches carry multiple satellites. As also noted here before, we have sent missions to every major planet in the Solar System, and a good many other objects.

I wonder if you could get a bunch of cubesats and such that are little more than a radio, a camera, and a power source, and have rockets just launch them into an appropriate trajectory of something you want to take pictures of. Don't even bother with having them make adjustments to get into a stable orbit around the objects - just get them close enough to take pictures you want before they crash into the object or (more likely) go flying off into space forever.

Brett said...

This is (slightly) tangential, but what did you think about the "no methane" news out of Mars?

Brett said...

Sorry about the third post. It's just my first post seems weirdly phrased to me now. Possibly the perils of making at argument at 1 AM in the morning.

jollyreaper said...
This comment has been removed by the author.
jollyreaper said...

track

Anonymous said...

If we had a destination, there'd be more traffic; we have to mount a major expedition to some place to build a destination; we need to lower costs to be able to afford to mount a major expedition...any way you look at it, it's gonna cost a train load of money to get the whole thing started. However, if we really did want to, we could, we just need to know that it won't be easy, cheap, or fast. Personnally, I believe it to be worth it. What about everyone else?

Ferrell

Brett said...

I think we need to take small steps that leave infrastructure in space that has to be maintained, which appears to be easier to justify to our government than a program that hasn't gotten anything off the ground aside from occasional tests. Anything that doesn't have hardware in space after 4-8 years is probably just going to get cancelled when a new President comes into office.

That doesn't exclude destinations, but it means you have to get there in small steps.

@Damien Sullivan
Somewhere out there is a web article by someone arguing the gov't should commit to daily launches, to bring the price down and see what happens. IIRC.

That's what I've thought as well. If you dedicate some sum of money (possibly slightly less than $1 billion a year) towards subsidizing a set of launches so that the launch cost per launch is quite low, then you might be able to build something useful from it. That would pay for part of at least a few launches and a regular launch schedule, it would be small enough so that it might survive the inevitable onslaught during budget time, and it would eventually develop its own constituency if companies and non-profit groups were using it.

The only downside is that it might displace private launch companies, unless they were brought into it.

Cordwainer said...

Used to live in Paso Robles, Eberle and Locatelli make some good wines in that region if your into that sort of thing. F9's out of French Guiana daily would make a lot of sense but I'm sure the U.S. and others would raise a fuss about the possibility that such technology could be capitalized on by less developed nations to create ballistic missiles just like OTRAG and Guinea-Bissau. Perhaps Reaction Engines Skylon concept would fair better.

I think putting fuel depots in space certainly constitutes "small steps in infrastructute". Problem is would it be all that useful for our current commercial use of outer space, which is mainly concerned with commercial satellite technology. Maybe if we replaced current monopropellant and ion thruster station-keeping systems with MEM's bipropellant systems it might make more sense since the heavy lift rockets could use the same fuel as your constellation of satellites. Which could in turn be accomplished with a "dumb" SSTO rocket-as-payload refueling/depot system.

Cordwainer said...

Personally I think International cooperation with subsidy of private venture via private contracts is the way to explore space the most economically. Problem is you have to get enough nations on the same page with the same development plan. A Lofstrom Loop or development of a new spaceplane like skylon would be the most amenable to those nations wishing to control ballistic missile technology. In fact their creation might even be used as a political carrot to get politically "rogue" states to stop their posturing and sign onto ballistic missile ban treaties and limit production of medium range missiles in lieu of using these new technologies for military applications. After all I'm sure the Iranians would much rather have "smart" technology that doesn't obliterate thousands of Arabs and Palestinians along with Israeli Jews if they could develop it or lay their hands on it. Just turn the Gaza Strip into the next big Space Launch Station so everyone's mutual interests are protected.

Eth said...

Cordwainer:
F9's out of French Guiana daily would make a lot of sense but I'm sure the U.S. and others would raise a fuss about the possibility that such technology could be capitalized on by less developed nations to create ballistic missiles just like OTRAG and Guinea-Bissau.

How so? France already has ballistic missiles, as well as most if not all of ESA's nations that want to. Though I see how the US may not want Arianespace or the ESA nations to have access to sensible US rocket or military technology, I don't see how it would give rocket technology to less developed nations.

The problem with distributing subventions to kick-start rocket industry is that, well, developed nations don't have enough money for it. Actually, those nations are for most living above their means, sometimes for decades, as seen by the dramatic budget cuts and/or tax raises that can be seen around.
If at some point in the future, economy is stabilized once and for all, states are reformed to be more efficient/less wasteful and ideally there are less wars around (armies are expensive), then it may be a good idea. Assuming that people in charge are competent at what they do, but if things improve that much, it can be assumed.
But with our current situation? It would be too much of a long-term investment, and no-one can really afford it.
On the other hand, private industry may help driving cost down, particularly if there are private interests that want to invest in it for space's sake, as we may be seeing right now.

Noclevername said...



"If at some point in the future, economy is stabilized once and for all, states are reformed to be more efficient/less wasteful and ideally there are less wars around (armies are expensive), then it may be a good idea. Assuming that people in charge are competent at what they do, but if things improve that much, it can be assumed."

Not going to happen. Besides, the developed nations currently spend far, far larger amounts of money on things with far less benefit, so the "we can't afford it" argument is right out the window. I know someone who is an accountant for a US government agency; let's just say we can use our current budgets much more wisely.

Cordwainer said...

Yes, many of the nations that are currently "partners in space" have ballistic missile technology. Hence the reason why they can be partners in space. What I was referring to is that many of the best launch sites our in areas or nations and that do not possess such technology or do possess such technology but are not part of any missile or weapons ban treaties. Also many nations would like to get their hands on "private" space technologies and working in poorer, less developed or politically contentious nations can offer extra challenges to maintaining proper security.

The argument that we can't afford it is probably off track as well it really comes down to what the public is willing to spend or invest and whether the project is deemed worthy enough for future profit by the business establishment. Fuel depots in space for maintenance of satellite networks would probably be profitable enough for those in the private sector to invest in, especially if it was well funded by a coalition of "space-faring" governments. Such a venture would in turn encourage the development of new launch vehicles and technologies as well as the creation of orbital space vehicles that run on a "common fuel and refueling system" to simplify the creation of such fuel depots.

It really comes down to someone presenting a pragmatic and coherent vision and plan for the future of space travel and being able to sell it to the public.

Brett said...

We need someone with money and a willingness to do a private space business to get into the propellant depot and transfer business, like a SpaceX for fuel depots. Right now, we just don't have a private company that's doing that, at least one that doesn't have any decent private funding like Musk was giving his SpaceX before they got commercial crew funding.

Also, it would be nice if there was some space-loving multi-billionaire who actually wanted to spend money on robotic space missions. But there's a lot of things that would be nice.

Brett said...

Sorry, I should clarify. It's not that there aren't companies doing orbital propellant depots and transfer, since there are - NASA gave some study contracts out on it, and MDA Corporation has a project wherein Intelsat is going to buy about 1,000 kg of the 2,000 kg of propellant they're going to launch into orbit.

But it's pretty tiny compared to the funding that other approaches are getting, despite the potential promise of such an approach. NASA should be giving this much more funding, and then giving some companies a free trial on it to see if they can make use of it.

. . . Of course, if we just go for cheaper, more frequently replaced satellites, then it might not be cost-effective. I've heard the US military is going that way in response to the possibility of anti-satellite warfare - cheap satellites that can be launched up quickly to replace ones shot down.

Brett said...

EDIT: Crap, news moves on. The Intelsat agreement is no longer in effect.

Brett said...

This thread sure has been quiet. What happened to our stable of commentators? Was there some form of angry stand-off in the previous post's comment threads?

jollyreaper said...

It's been a big gap since last post.

Cordwainer said...

Had to get sleep sorry. Well yes their is the argument that cheaper and smaller satellites make sense but that is an application argument. For more complicated research and communication satellites it would make more economic sense to use heavy lift rockets to launch larger more modular satellites with plug and play instrumentation/equipment modules. That way they can store more onboard fuel, use more powerful kick motors to raise or stabilize their orbits and can be updated with more advanced equipment over time thus allowing a longer shelf life. Of course you could also have a hybrid constellation of larger geostationary crosslinking satellites acting as hubs for a larger constellation of pico-sats. Whatever method you use though fuel depoting could still have advantages, particularly if you develop a mobile fuel depot or tug to service your satellites.

Anonymous said...

I think that most of the other commenters have said the way to increase rocket launches is to build an orbital infrastructure (like on-orbit refueling depots). That does seem like a viable method, and an orbital refueling depot would be benifitial to deep space exploration, whether manned or robotic. Can anyone think of anything else? I think we did discuss the possibility of an orbital repair garage several posts back, but it still seems like a good idea.

Ferrell

Cordwainer said...

Well as I said it would be advantageous if at least a portion of the satellites we put up be mor modular and plug and play so that we can retrofit them for a longer shelf life. Satellites typically have a long shelf life anyways and more modern satellites are becoming more modular so it makes sense especially if we have heavy lift technology to make those satellites more robust in their modularity.(sorry for the bad grammar)I would tend to opt for a more advanced and robust spaceplane/repair tug or reusable space repair tug vehicle that can be launched on demand as the next step. That way you can haul what you need to repair or replace satellite modules when you need to and not have to wait for long launch windows. In other words a Skylon that can reach high LEO, refuel in space and carry a substantial payload.

Eth said...

Noclevername:
Not going to happen. Besides, the developed nations currently spend far, far larger amounts of money on things with far less benefit, so the "we can't afford it" argument is right out the window. I know someone who is an accountant for a US government agency; let's just say we can use our current budgets much more wisely.

But that's precisely why government currently can't do it: money is used in so inefficient ways that they are badly overspending. Problem is, reforming that require time, efforts and, well, lots of money. (And both courage, skill and power, which is a very rare combination.)
So right now, with all the money wasted around, governments simply can't afford things like that. One way or another, this will have to change as at some point, there will simply be no money left. In the best case scenario, where efficient reforms are made, then they will have money to afford such things (though it may have to compete with other projects like fusion powerplants, sea colonisation, massive genetic projects and so forth.)

Until then, government simply can't finance such projects. Money would be too inconsistent (the next government may decide to gut it, particularly as spending less is in order nowadays), they may do it inefficiently (thus having no real effect in the end), not to talk about risks of corruption or political meddling...

So until governments are more efficient or economy grow enough to support less efficient governments, we shouldn't count on them to finance it. And I don't see either happening in the near future indeed.

But private space industry, while having less money to throw around and needing business angels to really take off, is in far better position to do it efficiently. Particularly as people financing it are really motivated.

Geoffrey S H said...

The problem with an orbital depot is that to reach said depot, craft on completely different trajectories need to spend an inordinate amount of propellant to change orbits. That's why NASA's orbital re-fueller craft study was such a disaster in the late 90's. Plus the fact that you have to lug that depot re-mass out of the gravity well, and have enough surplus propellant lifted for any number of missions. That will be horrendously expensive and isn't going to reduce cost in any way, otherwise we would have done it already.

If governments try to reform their spending habits, something somewhere else will be adversely affected. Thus they keep the status quo. There probably is no magic silver bullet to reform financing.

Tony said...

The difficulty with fuel depots is that to work at all they have to be in the same orbital plane as the serviced spacecraft. And even then spacecraft would use up a lot of fuel leaving their orbit stations, rendezvousing with the depot, and then returning to their stations. There's just no engineering justification for it.

About the only way fuel depots would work would be for support of interplanetary missions. But in that case they're only justified by the use of smaller LVs and modular mission design. The technical and operational risk of such an approach is at least the equivalent of operating large LVs, so there's still no point.

WRT launch-a-day, there's really no point to that either. Operating in space is so expensive to begin with that cheaper launch services are not really going to change anything. When your spacecraft life cycle cost approaches or exceeds a billion dollars (and they often do) then a $100M launch campaign becomes a marginal cost.

And before anybody goes there, no, cheaper spacecraft would not motivate cheaper launch services, or be motivated by them. You're just splitting up the same per-year life cycle sots into more pieces.

With all due respect to everyone here, tens of thousands of highly intelligent engineers have worked on these problems over the past 50 years. If there was a way to do things faster, better, or cheaper, they would have figured it out by now. Funny thing is, any interested layman can find out why things are the way they are. He just has to set aside the SF and coffee table books about spaceflight for a few dozen well-spent hours with Bate's Fundamentals of Astrodynamics (a little calculus helps, but is not strictly necessary), Encyclopedia Astronautica (astronautix.com), and a few technical histories (choose any ones that interest you -- the good ones all make the same points).

Cordwainer said...

So Tony would a mobile fuel depot or tug work better than having the serviced vehicle change orbit all the time. After all the depot would be carrying plenty of fuel along with it to change orbits. Also a shuttle used to service modular satellites would have go to those orbits anyways, so making it a fuel carrier as well as an equipment deliverer would sort of make sense wouldn't it. Also why you always citing old studies whenever you make a criticism. Ideas and technology do improve over time, not that I'm saying that the studies in the 90's weren't definitive. I did posit that for such a fuel depot system to work we would have to have a fair amount of modularity as well as improvements in propulsion. Did the studies in the 90's include ideas like momentum tethers or MIM's bipropellant rocketry.

Brett said...

Interplanetary launches would be a good reason for it, although I'd settle for using it to boost satellites into higher orbits from LEO. That's not an insignificant saving in Delta-V, especially if it lets you use smaller rockets with fewer stages to get your satellites/telescopes/whatever up into position.

@Tony
With all due respect to everyone here, tens of thousands of highly intelligent engineers have worked on these problems over the past 50 years. If there was a way to do things faster, better, or cheaper, they would have figured it out by now.

Yeah, I'm not buying that. Aside from the fact that the engineers involved in space-related projects actually are still working on this (at NASA and some private efforts), even the smartest engineers are limited by the funding and resources they are given. There are a lot of good things we could have done in space, if we had the money - the fact that we didn't doesn't mean that they're wrong from an engineering perspective.

Cordwainer said...

I do agree that more launches or cheaper vehicles won't bring payload cost, but they would allow one to build a more robust infrastructure in space that may have profitable uses for private companies here on ground in the telecom sector and other's.(like space tourism or weather forecasting) It is more a matter of whether someone wants to spend the money on that infrastructure. After all Falcon 9 will no doubt be very profitable in the future. New launch mechanisms like a Lofstrom Loop or Skylon could bring launch costs down and allow more launches on-demand in the far future. Electrodynamic momentum tethers could be used to launch fuel and other payloads to specific orbits where they would be collected by a mobile fuel depot in the same orbital plane that a particular satellite constellation operates in. For sure this means a highly specialized system of many pieces and it might be cheaper just to heavy lift a lot of fuel and replacement equipment modules to that specific orbital plane and then have your fueler/equipment tug collect those modules when something breaks. I'm thinking an autonomous repair system with fewer launches carrying larger payloads with lots of modularity, not lots of launches each with a specific mission and task.



Cordwainer said...

Won't bring payload cost down is what I meant to say. Although cheaper vehicle cost might bring the cost of some payloads down depending on the modularity of components.

Brett said...

By "have the money", I mean orbital fuel depots and alternatives to what we had. It's mostly gotten peanuts compared to what the space shuttle, heavy lifters, and space stations have gotten.

Cordwainer said...

I do think there has to be something said about the idea that more launches will lower costs. That is only partially correct. The only reason more launches would bring costs down would be:
1. If you have a high degree of modularity between launch components and orbital payloads.
2. If mass production of vehicles made vehicles cheaper and less massive.
3. If launch stations were more numerous and more robust in their infrastructure and therefore were able to support not only more launches but more launch vehicles.
4. If we were to push more of our commercial launches to heavy lift capability thus allowing one to insert multiple payloads into the same orbital plane with a single launch.
We could use heavy lift to launch a hybrid constellation of picosats and larger crosslink mother satellites to monitor and manage traffic between satellites, then launch a mobile tug to carry new equipment modules and fuel pods whenever the satellites need a refueling or retrofit. Heavy lift could in turn launch fuel pods and multiple replacement equipment modules as necessary throughout the satellites life-time with fewer launches. You would also have the benefit of launching infrastructure that could later be used for fuel depoting for interplanetary or cislunar missions.

Cordwainer said...

In other words high redundancy, high modularity, high autonomy and fewer launches.

Cordwainer said...

Or at least fewer launches for greater capability and larger amounts of infrastructure in space. Of course whether we need large constellations of satellites for our telecomm needs could be argued about. Also whether larger payload containers would allow for greater modularity in design could be argued over. Corporations tend to keep there product design proprietary so they can collect on patents and not have there ideas stolen so getting the private sector to agree on a common architecture may be difficult. That being said I would think with larger scale payload modules you could accommodate a wider set of equipment or vehicle designs.

Thucydides said...

Wow, it has been a long time since the last post.

WRT government spending; much of what a rational person would consider wasteful spending is generally payoffs to rent seekers, or padding for civil service wages, pensions and benefits, or bureaucratic "Empire building", and as such, is subject to perverse incentives which make eliminating these sorts of spending programs and boondoggles akin to going "over the top" in the Great War of 1914-18. You are attacking powerful, well entrenched and well funded (with your money) special interests who are willing to fight to the last taxpayer to maintain their privilages, perques and power. Anyone shocked to find out that the Republican Party establishment is funding opposition research against Senator Ted Cruz? He might upset too many applecarts and "special" relationships built up over the years....

I suspect that any changes in rocket launch technology will be driven by the military need to launch satellites at short notice to replace lost assets or perform short notice missions. This might imply cheap solid fuel boosters carrying small but capable spacecraft (think of the X-38 spending months on "black" missions before re entering Earth's atmosphere), or at the very least, boosters that can be rapidly "stacked" and fueled. Minuteman ICBM or MX missiles have been used for this purpose in the past, so nothing says assembly lines cannot be re opened (or new assembly lines using the lessons learned from past experience).

One other potential source of launch platforms might be ABM boosters. IF the US (or another nation) were to decide that ABM interceptors were necessary, then we will see assembly line production of boosters with a large amount of deltaV and cross range ability, with standard busses for the interceptors. In the US, we might see stations established on both coasts, Diego Garcia in the Indian Ocean and expanded basing in Alaska to cover the Northern Hemisphere. Using the standard busses (and possibly the technology for the interceptors) for small, capable satellites coupled to the boosters launching on ballistic trajectories rather than intercept trajectories might serve the purpose of rapid replacement and special mission access as well.

Brett said...

@Thucydides

Do ABM rockets get high enough to potentially reach orbit if you re-purposed them? I thought they usually tried to hit ICBMs in the ascent phase.

Agreed on the potential implications of the military moving towards easier-to-replace satellites.

Anonymous said...

I do have to admire how these threads evolve. Speaking of private space enterprises, what does everyone think about the Mars One project? A one-way trip to Mars to be part of, (what they call), the ultimate reality show? 100,000 have reportedly volunteered to go. If they pull it off, will it lead to other colonization efforts, or even just permanant off-world outposts?

Ferrell

Cordwainer said...

I tend to see Mars One as more a publicity stunt to get people interested in manned space travel than a serious boost in the arm to get us in that direction. Even a small semi-permanent base on the Moon would require enormous resources and could only be accomplished over time and with many small stages. While military technology might be repurposed or developed to facilitate smaller, cheaper more easily replaceable satellites. I tend to agree with Tony's assessment that payload cost can only be lowered so much. It might not cost as much to launch a multi-billion dollar pico-sat compared to a multi-billion dollar conventional satellite, but your still investing large sums of money. Which would you rather have quality or quantity. For something as important as a telecommunications satellite I would want quality, long life, redundancy and possible future expandability. While pico-sats might play a role in this I think you still need a robust network of multi-role satellites to accomplish this. Also we would have to beef up military delivery systems for some of the orbits and roles that certain specific satellites our currently used for. Not that certain production lines and programs couldn't be brought back on line or re-invented.
Also this fear of satellite warfare is likely overblown. Simply putting more infrastructure and redundancy in space can offset the cheaper is better doctrine. If they have too many targets to shoot at then it becomes to expensive to invest in an already expensive enterprise like satellite warfare. Also it is just so much cheaper to invest in cyber-warfare over satellite killers.

Cordwainer said...

While cheaper simpler satellite design is not going to cut it for most of the telecommunication needs of the modern world. One could argue that the military could get by with such a concept. One could take the opinion that the idea of Light Brigade Elements that can "do it all" is unnecessary and actually inefficient. Therefore most of the missions that the military performs doe's not rely on high-speed internet and state of the art communications. So having a bunch of dumb, low data-rate "bent-pipe satellites with a small dedicated constellation of expensive light weight "smart" satellites(for staff operations)might be more efficient than the current high data rate, high bandwidth Ku/Ka satellites in use.

Cordwainer said...

Mars has 2 percent water yet almost no methane, how odd. Maybe it's the scientific communities unfortunate habit of chosing atypical landing sites. After all they've had unusual luck with that in the past both with the Moon and Mars.

Damien Sullivan said...

At the risk of starting a political argument, I don't think the problem is governments wasting money. Most gov't spending is actually quite efficient at what it aims to do; as for whether the aims are good, the US is the only rich country that spends so much on the military. And as has been noted, the space budget is fairly small; doubling NASA's budget is small compared to the fluctuation is US war spending.

Current economic woes aren't from gov'ts spending too much, they're from unemployment rates being too high.

The real problem is there's no practical point to space other than satellites and research, and if only a small minority thinks space is wicked cool and worth spending on, that spending won't happen.

Re launch costs: I've heard, not confirmed, that launch is 20% of the cost of a satellite, which is in the spirit of what Tony said.

" unfortunate habit of chosing atypical landing sites"

What would be a typical non-ocean landing site for the Earth?

Geoffrey S H said...

"The real problem is there's no practical point to space other than satellites and research, and if only a small minority thinks space is wicked cool and worth spending on, that spending won't happen."


When someone in a position of power comes up with the phrase "do we need the full capability of space/satellites or can't we just go for something cheaper?" and unveils a reliable high-altitude dirigible to replace most satellite functions, that'll be the time to really worry.

Thucydides said...

Damien, the US spent so much money IOT contain the Soviet Union (even today much of the US military equipment, manning and basing is a legacy from that period), and to allow the devastated nations of WWII the ability to rebuild under the US military shield (with the secondary purpose of ensuring no nation or combination of nations would be able to challenge the US).

Most nations took advantage of the free ride, and many nations are now discovering that, hey its a dangerous world out there and, The US isn't as willing or able to do the heavy lifting any more.

Of course, the need to create a large and capable military force created the conditions for a vast army of rent seekers to grow up around the military (contractors, bureaucrats and even the uniformed bureaucrats that fill the headquarters), and the politicians who gain and maintain power by feeding this shadow army.

Since government spending distorts the market so much, large spending cuts would actually free up resources that could be used to invest in new technologies and markets, creating new jobs (it is estimated that simply eliminating duplicate Federal Government programs could save something on the order of $100 billion according to the US GAO. Suddenly puts that whole US deficit thing into perspective.

Yet this has been well known for years, but the Bureaucrats who measure their power in how many resources they control will fiercely resist shutting down "their" duplicate program, even if it is one of 80 programs that do pretty much the same thing.

"In the area of job creation, there are about 80 economic development programs spread among the Departments of Commerce, Agriculture, Housing and Urban Development and the Small Business administration."

http://www.bloomberg.com/news/2011-03-01/u-s-auditors-say-duplicate-ineffective-programs-cost-billions.html

I'm sure a little deeper Googling could find many more examples.

Brett said...

@Geoffrey S H

Too true, although I think we'll always have satellites for mapping the Earth's surface for military and civilian purposes at the very minimum. The blimps would be even easier to hit than satellites.

I see your point, though. Take away government payloads and government-funded launches, and the market for launches gets much smaller - the Wall Street Journal circa 2007 had it pegged at ~$2.7 billion (most of which was dominated by Arianespace). We're probably stuck hoping that a richer society (or at least a society with more super-rich people interested in space) will be willing to thrown around money on space stuff.

At least it's not a dismal hope. Look at all the billionaires chucking money after space-related projects - if it wasn't "Yay space!", they'd be pouring it back into investments.

I just wish they'd actually spend some money on privately funded robotic missions. $1 billion could buy you a good-priced robotic probe plus leaving money over to run the operations for it for a few years.

Anonymous said...

Thucydides; I like your anylasis of US bureaucrats...sounds like you've had some personel experiance with them...anyway, it seems like private interests are more likely to fund space expeditions than governments, at least for the time being.

As far as Mars One goes, we will have to wait until at least 2015 to see if anything happens...


Ferrell

Damien Sullivan said...

http://www.bloomberg.com/news/2011-03-01/u-s-auditors-say-duplicate-ineffective-programs-cost-billions.html

"on the order of $100 billion according to the US GAO"

No, according to Senator Tom Coburn. The GAO, whose job this is, does not try to estimate the level of duplication/waste.

"While the GAO report didn’t provide a specific estimate on the cost of waste and duplication, Coburn said it is likely to reach at least $100 billion"

Its specific examples are fairly small: 1 billion in farm subsidies to dead people, half a billion in DoD health care. Those 80 programs collectively spend $6.5 billion. Another 20 programs spend $2.9 billion on the homeless. Note that the waste (if any) isn't the total spending, but the duplicate overhead, a much smaller number.

Tom Coburn throws around big numbers but he's reliably full of shit, including his lead quote of "spending trillions and nobody knows what we're doing". In fact we know exactly what most of the gov't is doing: Social Security, Medicare, Medicaid, defense, food stamps and other equalization measures, and paying debt. The big three are very efficient at what they do; a libertarian might disagree with the goal of keeping elderly out of poverty and providing health care for poor people, but the programs are still quite efficient.

DoD budget is on the order of $460 billion. If they can save $460 million, that's not much. Even if total waste is 10x as much, that's 1% of their budget. 1% of the defense + discretionary non-defense budgets is about $12 billion. You could not quite double NASA's budget if you gave all of that to NASA.

You could save a lot by cutting defense a lot, but that gets into the politics of what gov't should do, not "easy" waste cutting.

Damien Sullivan said...

'“Some programs may offer similar types of services and serve similar populations, potentially leading to overlap and fragmentation,” the GAO said.'

That's really making a bold and clear statement, there.

80 jobs programs... why? Are they all doing the same thing? Or coming from different angles? Would putting them all in one big bureaucracy save much? After all, everyone "knows" that big bureaucracy is less efficient than small agile organizations, right?

"The Interior Department is in charge of salmon while they’re in fresh water, but the Commerce Department handles them when they’re in saltwater. I hear it gets even more complicated once they’re smoked,"

Yeah well the world is complex and doesn't come in neat boxes. Regulating freshwater and marine ecosystems separately seems decently sound on the face of it, but whoops, a fish crosses the lines. But if we had separate programs for salmon and trout fisheries someone could attack the duplication *there*.

'The USDA ensures the health of the young chicks that are supplied to egg farms, while the FDA oversees the safety of the feed they eat. '

Yeah and if those were part of one organization, they still might be handled by separate sub-departments. It's easy to point and laugh about duplication, and I'm not saying everything's perfect, but fixing things may be less obvious than it appears.

'On a single night in January 2009, there were about 643,000 homeless people, the report said. At least seven agencies spent about $2.9 billion on more than 20 programs in 2009 to help the homeless with shelter or housing aid.'

The most damning thing there is spending $4510/year per homeless person. That should be enough to house them all, even in expensive areas if cities allowed the building of microapartments. And doubling the number would be chump change and make things even easier.

Cordwainer said...

I have to agree with Damien on the point of government spending. Duplication of effort is not always a bad thing and sometimes it is very necessary. The real problem with wasteful spending is the cost benefit analysis of government programs. Many programs our inefficient but many our quite efficient and serve a worthy purpose for society. Cutting costs to the Big Three would have disastrous effects on our economy and would might only create minimal savings. Personally I think we need to raise the debt ceiling and increase our payments toward the debt. Put a Band-Aid on Medicare and make some minor adjustments and reforms to Medicaid and Social Security and make some minor cuts in defense. Where we could really change things is investing more in education, putting price controls on higher learning and healthcare and turning welfare into a job-training/education program. Obviously not everyone is going to be able to have a job even if they are well educated, but those that can't get employment will at least have the education to create their own business or find jobs in foreign countries.

As to the development of outerspace as I have said before I think it is something we need a clear vision of how we are going to go about it on an international level with both international and private funding. Like climate change it is one of those issues that requires a global approach.

Anonymous said...

I'm with Tony on the value of fuel depots. It's a good idea to support a single big mission or destination, but not to support multiple missions that will be in different orbital planes. It will take too much delta V to to get back and forth to the depot.

Looks like we're forgetting that we already have an orbital space infrastructure, the International Space Station. Ten of the launches this year were missions to the ISS. That's almost 1 in 5 launches.

Now if someone could convince the governments that operate the ISS that we need another space infrastructure project, such as an Earth-Moon L2 station or a small moon base, then human spaceflight takes another step.

A LEO fuel depot might be a good idea to support Lunar operations.

Ron

Geoffrey S H said...

If you could refuel something like a Saturn V, then you could send that into orbit, attach a new third stage you sent up there a few months prior, and then send it on its way. Less a method of extending the range of a craft, and more like allowing long-range missions without needing anything on the launch pad bigger than the monsters we already have.

Cordwainer said...

Well tethers in low orbit would allow you a way to boost craft and fuel to higher orbits without the use of fuel depoting or long range heavy lifters. Such an infrastructure might allow you to use smaller rockets only once in place. Of course one would have to use heavy lift or lots of medium size rocket launches to get that infrastructure up their. Station keeping costs in fuel for the tether shouldn't be that bad if they are close enough to the geomagnetic field to use electro-dynamic forces to maintain orbit. Electro-dynamic tethers might also be a cheaper way to "tug" satellites to higher orbit in some cases. Also an autonomous dedicated mobile fuel depot that moves between orbits, intercepts and refuels satellites could reduce reduce the number of launches necessary to refuel craft in close proximity to one another. If it's already up there then the delta vee and fuel costs to change orbit should be minimal compared to launching a refueling craft from Earth to an intercepting orbit. More efficient motors or various tether-based or sail based propulsion could be used for such an autonomous fuel depot. Also when you need to refuel the depot it could drop to a lower orbit thus reducing the fuel costs to refuel the depot from Earth.

Cordwainer said...

Personally, I think for long term exploration of space depoting is of more value than the ISS. Space habitats are useful for studying the effects of deep space exploration on the human physique and it does offer a good platform for various scientific experiments. On the flipside though to really study the human effects of deep space exploration we would have to place a space station outside the Van Allen belt (to test things like radiation shielding) and most of the experiments that can be carried out on the ISS can be replicated here on Earth.(some easier than others though) I really think we need a clear vision and international cooperation towards manned space flight and the creation of a semi-permanent base on the Moon with orbital maintenance and refueling infrastructure and creation of a more modular standard for communication satellites as part of the deal to "sweeten the pot" for private investors.

Anonymous said...

Hey, Rick, did you catch the launch of the Falcon from Vandenburg today? I'd love to be able to see a real launch in person. Well, some day...
Anyway, maybe building an outpost on the moon or at L4 or L5 might boost the frequency of rocket launches, to resupply it and rotate crews. Of course, you'd have to have a very specific mission to be performed by said outpost, so as to make it attractive to investors, either private or government. Again, we just need to be willing to spend the money and make the effort, and those seem to be the hard parts.

Ferrell

Tony said...

Let's see...

1. Engineers could solve problems better if they had more money...

Maybe. Sometimes. But it turns out that Apollo, with all the money NASA could find ways to spend, was still just an expendable return capsule, on top of an expendable service module, on top of an expendable lander (which in turn was an expendable descent stage on top of an expendable ascent stage), on top of an expendable rocket on top of two expendable stages of launch vehicle.

Physical laws aren't any different for us now that the were then.
No amount of money is going to overcome the energy requirements to get into orbit. No amount of money is going to change the amount of energy one can extract from a given set of chemical reactions. No amount of money is going to develop lighter material structures that can also manage the stresses of orbital launch or space flight -- if it could have it would have, given the dollar value to spacecraft operators of every extra pound of payload per pound of launch vehicle.

When you're up against the physical constraints of your environment, money isn't the answer.

2. Fuel depots, part deux...

What seems to be missing in this discussion is the fact that whatever delta-v one has to carry to reach a higher orbit has to be carried up to the fuel depot plus the delta-v to put the fuel depot tankage, propellant management machinery, plus the spacecraft refueling interface. The spacecraft also has to carry a refueling interface as well. That's all mass that has to be put in orbit. It's not mass that has to be put in orbit (except for a little extra tankage mass on the spacecraft and the propellant to move it to the final orbit). So, once again, the fuel depot makes sense for extending the capabilities of a certain size of launch vehicle, for a very limited variety of missions. It's simply not a solution to most problems.

3. Modular spacecraft...

Similar to fuel depots, this concept involves all of the penalty mass in interface hardware needed to join modules. Not to mention the penalties of locking oneself into a legacy interface technology for the life of the spacecraft. Operating in space is so expensive to begin with that fully integrating and internalizing all life cycle resources into the spacecraft makes the most sense.

4. Refueling large spacecraft in orbit...

Makes more sense to just send up extra dockable stages with their own engines. Same number of launches, same number of docking operations, same number of engines (because the refueling stage will almost certainly have to do the final orbital insertion on its own, or with the thrust from an attached upper stage engine). The real risk decision is whether to accept the risks of orbital refueling or the risks of engine restarts in orbit. One we barely know much about at all, and only on a small scale. The other we've had ironed out for over four decades.

Tony said...

5. Orbital tethers...

If you don't have as much mass going down as you have going up, you drop the tether's altitude every time you release something from the top end that you attached at the lower end. As long as we have mass mostly going one way into space, tethers are just a different way of burning propellant, because you have to constantly keep boosting them back up to operational altitude.

Damien Sullivan said...

I thought Apollo took the form it did because of deadline constraints, not physical ones, i.e. it seemed easier to get working by 1969. Vs. the "launch to Earth orbit, bus over to the moon" model.

I also thought tethers could use electromagnetic coupling with the Earth to trade power for altitude, avoiding a need for propellant or mass balance.

If it's true that 80% of the cost of a satellite is non-launch, modularity/mass production could potentially be worthwhile even with a mass penalty.

Conversely if launch costs dominate, a 10% increase in mass for refueling options could be outweighed by a 50% drop in costs due to "mass production" launching making full use of the ground infrastructure and labor force... assuming, again, that you had the volume of demand to justify the increased total cost.

Anonymous said...

Tony is right about the harsh realities of spaceflight.

We do have experience refueling large spacecraft. Each Progress resupply ship transfers over 800 kg of fuel to the ISS. What we don't have is experience refueling satellites. Still, the ISS experience doesn't solve the issues with fuel depots.

Maybe engineers can make incremental improvements, but what is needed is more money to build more of what we got.

Commercial operations like SpaceX and Orbital could reduce costs a little by removing some of the government bureaucratic foolishness. That still doesn't make launches cheap.

Ron

Tony said...

Damien Sullivan said...

"I thought Apollo took the form it did because of deadline constraints, not physical ones, i.e. it seemed easier to get working by 1969. Vs. the 'launch to Earth orbit, bus over to the moon' model."

Project Apollo and its expendable infrastructure was initiated a year before Kennedy set a time constraint. Kennedy's speech was in fact predicated on what NASA thought it could do with projects and plans currently in-hand. The perceived von Braun architecture of stations, shuttles, and lunar exploration vehicles had already been abandoned by von Braun himself, in favor of systems like those eventually delivered and flown.

"I also thought tethers could use electromagnetic coupling with the Earth to trade power for altitude, avoiding a need for propellant or mass balance."

Where does the power for the electromagnets come from? And how powerful do these electromagnets have to be (and how big a power plant does one need) to compensate for presumably hundreds to thousands of tons per year boosted perhaps an extra kilometer or two per second? How much delta-v is consumed putting that infrastructure in place? As always, TANSTAAFL.

"If it's true that 80% of the cost of a satellite is non-launch, modularity/mass production could potentially be worthwhile even with a mass penalty."

Nope. The limiting factor is that pounds of mass devoted to interface hardware are pounds of mass not devoted to mission hardware. Increased or upgraded capabilities are better packaged and utilized in replacement spacecraft. Remember, modularity presumes that some basic spacecraft bus can last long enough in orbit to reliably service newer attached modules. Given what we know about the space environment, that's not the way to bet.

"Conversely if launch costs dominate, a 10% increase in mass for refueling options could be outweighed by a 50% drop in costs due to 'mass production' launching making full use of the ground infrastructure and labor force... assuming, again, that you had the volume of demand to justify the increased total cost."

Problem is, there's almost no conceivable future in which there is enough traffic going into the same orbital planes to make that worthwhile.

Unknown said...

Well, SpaceX did just perform its first launch of the upgraded Falcon 9 rocket. If they ever get it working, the reusable first stage will cut their launch costs dramatically.

If we're honest with ourselves, we all realize that the main problem with the launch costs is simply the lack of willingness for countries to pay those costs and the lack of the ability for private citizens and institutions to cover them. The whole reason we seek to reduce those launch costs is a way of avoiding the penny-pinching of short-sighted governments and market launch services to people who have the vision to really open up space for future generations of humanity. SpaceX and Orbital Sciences are making progress in that regard, but the first problem deserves to be attacked too.

Tony said...

Kyle Allen said...

"Well, SpaceX did just perform its first launch of the upgraded Falcon 9 rocket. If they ever get it working, the reusable first stage will cut their launch costs dramatically."

Assuming facts not in evidence. Judging by Shuttle experience, it may cost them as much to refurbish a stage as it does to just build a new one. That likelihood is increased if you take into account the payload not flown because mass budget had to be spent on vehicle recovery.

"If we're honest with ourselves, we all realize that the main problem with the launch costs is simply the lack of willingness for countries to pay those costs and the lack of the ability for private citizens and institutions to cover them. The whole reason we seek to reduce those launch costs is a way of avoiding the penny-pinching of short-sighted governments and market launch services to people who have the vision to really open up space for future generations of humanity. SpaceX and Orbital Sciences are making progress in that regard, but the first problem deserves to be attacked too."

Please, oh please, oh please...don't talk about "vision". Vision won't get anyone anywhere. having something profitable to do in space will move the needle. So far, the stuff you can make money on in space doesn't need humans. Even when you count the things that can be done where the return is measured n knowledge, one really doesn't need more than a few humans at a time. Whatever the vision was or is, the reality is that space doesn't need us -- ourselves, in person -- all that much. And it likely never will, as long as we're getting there with chemical rockets, no matter who's making them or flying them. There's just not that much savings to be realized by any realistic business or operational model.

Those are the facts. Hard facts, for a lot of enthusiasts and dreamers, but still the facts.

Brett said...

@Tony
What seems to be missing in this discussion is the fact that whatever delta-v one has to carry to reach a higher orbit has to be carried up to the fuel depot plus the delta-v to put the fuel depot tankage, propellant management machinery, plus the spacecraft refueling interface. The spacecraft also has to carry a refueling interface as well. That's all mass that has to be put in orbit.

I'm not sure what your argument is here. We already know that the depots would require more launches in general to get everything up there, but that's a given. The question was whether it would be cheaper to do a bunch of launches to boost stuff into higher orbits and/or interplanetary space after re-fueling in LEO, as opposed to building and launching a smaller number of heavy lifters.

I do like the idea of attachable second stages, although you're still doing the same work of rendezvousing in orbit.

Please, oh please, oh please...don't talk about "vision". Vision won't get anyone anywhere. having something profitable to do in space will move the needle.

True, which is why I don't think profit will be the primary driver of any sort of human expansion off-world (expansion into suborbital areas and LEO maybe). It will instead have to come from a private effort by people with enough pooled money to make a go at it, which isn't likely in the near future.

"Never" is a long time, and stuff that's way out of budget for anyone without government money now might not be so in the PNF and PMF. We've already got a couple billionaires throwing around money on this stuff, and not just because of some distant possibility of making money - Musk alone could probably make much more if he'd spent the money elsewhere.

As I mentioned up-thread, the real pity is there are a bunch of cool robotic missions that they could afford now if they pooled money, but won't because the manned missions get most of the glamour. The guys throwing around money on New Space stuff could probably put together the $2 billion for a Flagship-Level Mission with NASA (particularly if they partnered with NASA on it), and money beyond that for the operations side of it.

Cordwainer said...

Thank you for grounding this discussion in hard facts Tony. I do tend to think though that there are still some engineering possibilities that would make depoting and certain amount of modularity in the satellite market worthwhile though. Otherwise engineers wouldn't still be looking into them. Depoting is currently being studied by NASA and satellite and rocket designs have become more modular than they were in the past. Maybe vision won't get us much of anywhere(although it did seem to work for Apollo) but hard work and imagination can certainly give us those incremental improvements you failed to explain fully.

Which brings up the question is there anything you are optimistic about when it comes to new launch technology? Falcon 9's reusable architecture seems quite plausible and cost effective to me and Falcon Heavy would seem to open up a number of possibilities in the are of getting more of what we already have up into orbit. For instance what do you think of Micro-fabricated chemical propellant rockets for station keeping could they offset some of the current fuel costs compared to conventional thrusters.

Brett said...

@Kyle Allen
If we're honest with ourselves, we all realize that the main problem with the launch costs is simply the lack of willingness for countries to pay those costs and the lack of the ability for private citizens and institutions to cover them.

This. Although I suppose we ought to be grateful that Space Exploration has gotten as much funding as it has, when you consider that most trans-Earth-Moon-system missions don't have direct applicable potential applications in the way that medical research (for example) has. Other fields aren't so lucky - Deep Sea Exploration gets peanuts compared to what we spend on space exploration, unless you want to count the money spent by oil companies looking for undersea wells.

In general, we Americans just spend a very small fraction of what we could on any scientific research when you consider how large the government budget is. Even the National Institutes of Health, who can go to Congress and say that their research will directly help efforts to find cures for major diseases, gets about $26.4 billion a year - 0.7% of the Federal Budget. You can't buy your way towards a Cure for Cancer*, but more money sure would you let run more trials and experiments, and check the duplicability of the promising trials you have run.

* Yes, I know "Cancer" is actually a blanket term for hundreds of different diseases.

Brett said...

@Cordwainer
Thank you for grounding this discussion in hard facts Tony. I do tend to think though that there are still some engineering possibilities that would make depoting and certain amount of modularity in the satellite market worthwhile though. Otherwise engineers wouldn't still be looking into them.

It's good to have Tony around as the Resident Curmudgeon, even when you disagree with him. It keeps us from developing that kind of "High-Low" feeling you can get at places where optimism about space technology runs unchecked: "High" optimism about what the technology can do, "Low" happiness about how all it needs is for NASA to re-allocate their funding towards it.

Cordwainer said...

True enough Brett which is why I think the only way we could have the type of infrastructure in space I have been pushing for is if the international community were to foot the bill. No one nation or private enterprise would be willing to. If we leave it to private enterprise we will have more of the same with incremental improvements. If we leave it to individual governments we will have more of the same along with numerous different standards and engineering builds. At least the private sector will chose some common set of standards for interoperability when it profits them to do so. Problem is developing an international effort towards a common goal in space is highly unlikely. The best we might hope for is some kind of international build standard for satellites and space vehicles like what they did for the internet and computer industry.

Tony said...

Cord:

The reason we have NASA budget line items for unlikely technologies is that some Congresscritter wants it that way. If you follow the politics of fuel depots, for example, you find out that they're the favorite of Congresspersons who would have benefitted from evolved Delta, had it been picked over the Shuttle-derive Space Launch System. Otherwise, they have no real purpose.

Otherwise, what am I optimistic about? Depends on the context of the optimism. If the context is realistic manned space exploration, I'm reasonably optimistic that NASA is far enough down the road with SLS that it might actually fly, in which case manned missions beyond LEO might actually happen again. If the context is dream castles in orbit, on the Moon, on Mars, or in the asteroids, I'm quite pessimistic about otherwise intelligent people being able to come to terms with reality -- or should I say the unreality of those things. As much as I criticize Cause Guy, that's my hopeless cause -- trying to get such people to learn a little real world astronautics and astrodynamics, which would in turn help them understand why things are the way they are, which in turn might actually make them a little less dissatisfied with the way things are going in manned spaceflight.

Cordwainer said...

So what is exactly wrong with the cost-efficiency or lack thereof in evolved Delta. Leaving depoting aside seems like such systems would not be that
costly compared to other methods in use or being explored. Sure it would be less efficient compared to some other methods in use but would certainly not be as taxing as some space programs the public has been willing to spend money on.

Also what would the point be to have manned missions beyond LEO if we aren't going to build "dreamcastles" it doesn't seem like we could really do all that much that Apollo or a host of robotic probes could do, unless we are willing to devote money to some type of semi-permanent base or permanent base on the Moon. Otherwise it would be difficult to support a long-term scientific mission to the moon. Doesn't seem like sending separate teams of astronauts to the Moon for a couple weeks at a time would really allow them to accomplish that much from either a research point of view or in terms of pie-in the sky dreams of colonization.

Which brings up the question do you think space colonization is pure folly or something that could be reasonably done in the far future, Tony?

Cordwainer said...

Personally my opinion on the whole affair is not one of a starry eyed dreamer by the way. I think there are far better things to spend our money on than space exploration and for the near future I think governments should stick to robotic exploration missions. I just feel that we shouldn't sit around forever and wait for Atlas to shrug out manned space missions. It's just not in the cards at least not in the near term. Satellites will be the only profit that the private sector can rely on for a long time to come. The only way we can create opportunities for further profit is if we do create the equivalent of "highways in space" through intergovernmental cooperation. That being said I don't think we should invest in manned missions until we develop more efficient launch methods and space infrastructure on the whole. Let the private sector squeeze the costs down and invest in research towards new launch and propulsion methods and in a few decades from now we might have something.

Cordwainer said...

By the way what is everyone's opinion on Skylon or other HOTOL methods?

Also, Tony you never did answer my question about micro-rocketry for station keeping. What is your opinion of Lofstrom Loop or other launch loop technology? Would it be of any benefit? Would it be worth the cost?

Noclevername said...

My view is that colonization is a worthwhile long-term goal to work towards, but it will have to be achieved in steps and stages. For example, beginning work on closed-cycle ecosystems for spacecraft is research we can do right here on Earth, at relatively low cost, even before we start to develop a space infrastructure.

Anyone who expects us to snap our fingers and throw all NASA's budget into building a full colony right now does actually fit the description of a "starry eyed dreamer", but not everyone who looks forward to a permanent human presence in space someday falls into that category. Even NASA itself describes that a plausible long term goal.

Brett said...

@Tony
If the context is realistic manned space exploration, I'm reasonably optimistic that NASA is far enough down the road with SLS that it might actually fly, in which case manned missions beyond LEO might actually happen again.

That's interesting. I'm pretty pessimistic about its future, and think it will probably get canceled or worse, budget-cut-and-delayed into oblivion once we get a new President in 2017 (and his/her choice for NASA Administrator).

. . . . But Florida politics seem to be in its favor, so maybe it will survive in some form. Florida is still a swing state.

@Cordwainer
Doesn't seem like sending separate teams of astronauts to the Moon for a couple weeks at a time would really allow them to accomplish that much from either a research point of view or in terms of pie-in the sky dreams of colonization.

I think you'd learn some good stuff, although the case for human explorers isn't as strong as it is for farther out destinations like Mars. The Moon's close enough that you could control rovers on the surface from Earth with only a few seconds delay, if you had the relays set-up (which can be trouble - the Moon tends to be weird on orbits IIRC because of the areas of higher mass).

I'm mildly supportive of space colonization, although I think it's too romanticized. Somewhere down the line, I think a group of people with enough pooled money to try it will, assuming a colony doesn't grow out of some long-distance research space station like Rick has predicted.

That said, I'm not certain a colony will be viable, and it's easy to imagine a situation where permanent space habitation never develops. Space would be like oil platforms and research ships in the sea - people go there to work and research, but not to live permanently.

Side-note, but has Rick ever done post speculating on what might have been if the whole US-Soviet Space Race had never happened? I think we've had speculation on what might have been if the Apollo Program had never happened. I'm not sure the alternative would be better, because without NASA as an institutional bulwark for space exploration, space projects might be like trying to get funding for particle colliders in this country.







Tony said...

Cord:

I'll start with the micro-rocketry because not commenting on it was an oversight on my part...

Figure an orbital station keeping engine weighs about 1 kilogram. Figure it has a thrust to weight ratio of 25. (Which is actually somewhat conservative: MR-107 has a T/W ratio of 29.37 on an engine mass of .89 kilograms.) Figure a micro-rocket with a thrust ratio of 1,000. That gives a weight factor of 40:1, traditional monopropellant hydrazine to micro-rocket. That means you save .975 kilograms per engine. If a spacecraft has a total of four station keeping engines, you save less than four kilograms. That extra mass could be put to some use, sure, but it's only a marginal savings.

In other news, the purpose of putting a man on a mission is that there are some things robots just can't do when it comes to field geology. There's also a strong argument that having a person go and see for himself is a valuable benefit to the human race. But only a few people are needed per mission to accomplish both goals, not hundreds or thousands or millions.

WRT space colonization, it depends on what you consider to be the "far future". I think that it's possible -- not certain, but possible -- that the human race will exponentially increase its permanent cohort in space by some small factor per century. If you choose a factor of five, then space colonization reaches ten thousand (O'Neill's initial goal, IIRC) in something over five and a half centuries. If you choose a factor of ten, it takes you four centuries to get there. If you choose a factor of two, the far future is over 1,300 years away. I don't know what the answer will actually be. (and it could be never; like I said, nothing is certain.) But recent experience suggests a factor of between two and four. So figure the far future (defined as the O'Neill threshold) to be something like 600+ years down the road.

Tony said...

Brett said...

"That's interesting. I'm pretty pessimistic about its future, and think it will probably get canceled or worse, budget-cut-and-delayed into oblivion once we get a new President in 2017 (and his/her choice for NASA Administrator).

. . . . But Florida politics seem to be in its favor, so maybe it will survive in some form. Florida is still a swing state."


It survived the recession. It's rationale is a realistic goal of having a reliable way of putting Americans in space, on American vehicles, and using those people in space to accomplish reasonable near-term achievements. It's evolving Shuttle hardware into a single, multi-purpose super-heavy lifter. It's not so strongly linked to Obama or Bolden that a change of administration is going to cause it to be seriously revisited. That makes it so unlike VSE -- and so much more realistic in terms of budget -- that it has a good chance of actually flying. Not a perfect chance, but I'm thinking in the ballpark of 95%.

Noclevername said...

"But recent experience suggests a factor of between two and four. So figure the far future (defined as the O'Neill threshold) to be something like 600+ years down the road." --Tony

The trouble with using recent history as a benchmark is that we are in a transitional period as far as manned space flight is concerned. The previous era had space travel as strictly a big-budget pork-processing government monopoly, and at present the private space travel industry is in its infancy, practically pre-natal. Trying to predict that far ahead in what is presently a rapidly changing and evolving field is somewhat impractical IMO. That's why I don't put much faith in specific timeline schedules for developing trends, especially something that will take several generations. Just look at the changes between, say, 1870 and 1970. The world became a far smaller place, travel and communication became nearly unrecognizable to people of the earl time, and we landed on the Moon only a decade after the common wisdom insisted that such an act would be centuries or millennia away.

Cordwainer said...

I don't think anything I have suggested would give the impression that I'm dissatisfied with the progress of manned spaceflight by the way. If anything it seems that Tony might be the one who shares the dissatisfaction of one who is so jaded that they have to Scrooge even the most reasonable of ideas.

By the way what is the difference between a mobile fuel depot or tug and dockable stages with their own engines, sounds pretty close to the same thing, eh? I mean it's pretty much a dedicated tug right, adding hardware for fueling capability wouldn't increase launch mass that much. Most satellites as well as the space station already have some sort of refueling or fuel pod replacement technology built in. ISS refueling has already been mentioned and the Space Shuttle repaired and refueled a number or satellites during that programs lifetime.

I am merely suggesting that technologies could be developed for a reasonable cost to extend the life-cycle of satellites so you don't have to replace a whole satellite just modules. Whether that takes the form of more launches for more money is questionable. After all Heavy Falcon and other launch technologies could reduce that cost. Also sending up modules and fuel pods rather over an entirely new craft should actually lower the mass penalty slightly as well. Most communication satellites have similar design constraints so creating a modular design or a set of modular designs should not be impossible. Obviously for other satellite types like research and observation satellites it would depend on mission type so modularity would not be very cost effective. While you would want to keep your tug, mobile "space dock" in the same orbital plane there are only a few orbital planed that communication satellites operate in so the amount of such hardware needed doesn't seem a game-ender.

Of course you could always develop self repairable satellites that would remove old modules and grab new modules orbitally inserted into their flight paths this wouldn't require any long term infrastructure but would require some increase in the mass or your satellite. Plus a satellite with robotic arms just looks too cartoony. You could still use a Falcon Heavy to deliver a bunch of modules or fuel pods to a specific orbit and then have your deep space craft pick them up along there way out of Earths gravity well. Of course they would lose some delta v trying to rendezvous with said modules but they could use a gravitational assist maneuver to pick up some of that lost delta v. If the rendezvous provides enough fuel or a more efficient drive system then you could extend your vehicles range considerably.

Probably be useless for a Moon mission though you would be better off doing a straight shot. Fuel depoting on the Moon or in-situ refueling along with a dedicated orbitally launched Moon Shuttle would offer some advantages at least in making the trip considerably quicker. Albeit such a system would not be terribly cost effective or justifiable compared to an Apollo style Moon shot.

Was surprised about less methane on Mars, was even more weirded out by the fact they found so much water. Even if life never existed on Mars I would think there would be more methane than what was found. I'm chalking it up to an atypical landing spot and/or some unknown as yet natural phenomenon. Maybe some sort of reductive life form ate all the methane, Hah.

Cordwainer said...

While a small team of astronauts on the moon could do a lot. Rotating teams of astronauts living out of a lunar based research facility could probably do a lot more. I wasn't suggesting a large "colony" like station, just a research station that might be used to study long term habitation on the Moon as well as possible exploitation of lunar resources. I agree there is no reason to have space colonies anytime soon, and I would tend to agree with Tony's timeline as being the baseline for any future timeline that doesn't include alien invasion or anti-gravity.

The only profit in space other than satellites is orbital beamed power stations and mining. Both of which would require some intensive use of Earth's resources to push up that timeline beyond 500 to 600+ years. Even if we develop cheaper launch technology within the next century, like a Lofstrom Loop or Rotovator. One would have to have the economic rationale to build it and even then there wouldn't be much need to go mine the Moon unless you were really desperate or if Helium3 fusion becomes a reality. We're more likely to see beamed power stations and space hotels before we see colonies on the Moon, and even those seem far fetched in my opinion.

Cordwainer said...

BTW Tony what would the fuel saved calculation be for a hypergolic bipropellant micro-rocket over a conventional hydrazine monopropellant system. Mass savings isn't the only thing to take into account. Higher thrust for kick maneuvers(over hydrazine or electric propulsion on conventional systems) and reasonably more efficient propellant flow and burn have to be factored in as well.

Noclevername said...

Colonization will not happen as a result of an economic rationale, but rather will become a driving force for one. The profit will come from selling lift and delta-v to would-be colonizers, successful or not. It's a niche market, granted, but with a planetary population of 7 billion and growing, it need not be a majority to provide the needed potential for solvency.

Noclevername said...

I see things going this way:

First, private industry and advancing tech bring down launch costs. A space tourism industry slowly starts to develop. The first space hotels are clusters of inflatables in LEO, with some rented out to scientists both government and private.

At first only Earth-launched materials will be used. Spin sections will be built for the space-sick or for staff who must spend long periods in space.

Sample return missions will eventually give way to larger-scale ISRU collection of things like water and regolith from the Moon and NEOs, via things like the Kuck Mosquito robot. These will be used as propellant, shielding and building materials, as the infrastructure to mine and process space-based materials grows. As ET propellant gradually gets cheaper and space drives improve, space tourism and manned exploration will eventually move beyond Earth orbit. Life support systems will be forced to improve as well.

The first crude human Moon bases will be established. Robot mining on the Martian moons will lead to a manned Mars landing. Tourism will follow, again only for the rich at first. Would-be settlers will no doubt try to colonize at this point, probably ending in failure to poor planning or inadequate balance of the ecosystem. This will dampen, but not eliminate, the enthusiasm for ET settlement. So will try again, and sooner or later, some will succeed.

Note that I've given no dates or time estimates. IMO it's physically possible that such developments could happen within a century, but more likely two to three. I can't really see it taking more than that for the first attempts to be taken. How long it will be before the colonists actually master the needed skills and lifestyle is dependent on a number of human variables and is not predictable.

Tony said...

1. Transitional period WRT manned spaceflight: Fantasy. Period. Space tourism isn't going to happen in any greater volume than it already has. A few billionaires will be able to afford it. Maybe. If that's what they want to do with a few hundred million apiece. (Because the Russians aren't likely to subsidize it any more.)

As for rapid evolution in spaceflight technology, I suggest you spend a few hours on Encyclopedia Astronautica, paying particularly close attention to launch vehicle efficiency numbers over the past sixty years. Rockets matured quickly and have been up against fundamental physical and chemical constraints ever since.

2. The difference between fuel depots and dockable stages is experience. Since we have so much experience with engine restarts in space, and so little experience with fuel transfer -- and no experience of transferring cryogenic bipropellants -- we'll likely never get around to fuel depots, simply because we already have an adequate technology in multiple stages.

3. Modular spacecraft. For at least the third time, the problem with this idea is needlessly devoting mass to interface components, locking into an interface technology, and the fact that whatever you plug the modules into degrades too. It just makes more sense to build spacecraft that are designed to endure the nominal mission lifetime, then de-orbit and replace the total package.

4. Storable bipropellants are about 25% more efficient than monopropellants. However, bipropellants require two tankage systems. That's likely to wipe out that 25%.

Noclevame said...

"1. Transitional period WRT manned spaceflight: Fantasy. Period. Space tourism isn't going to happen in any greater volume than it already has. A few billionaires will be able to afford it. Maybe. If that's what they want to do with a few hundred million apiece. (Because the Russians aren't likely to subsidize it any more.)

As for rapid evolution in spaceflight technology, I suggest you spend a few hours on Encyclopedia Astronautica, paying particularly close attention to launch vehicle efficiency numbers over the past sixty years. Rockets matured quickly and have been up against fundamental physical and chemical constraints ever since.
"

As I said, looking at the politically constrained missions of the Space Race era for examples sheds absolutely no light on what private companies will accomplish.

Yes, conventional multistage rockets reached their physical limits so far; that does not mean they are anywhere near as cheap to launch as they can be, due matters that have nothing to do with engineering or practicality. That is why NASA started COTS and now started using private carriers to supply the ISS. It's cheaper.

It does not mean technology can't change the game. HOTOL looks to be on the verge of fulfilling its promise within a generation or two. The Lofstrom loop is one long-term solution.

And the cost of conventional rocketry is already coming down. The demand for space tourism is there, the main thing preventing it is cost. Just as mountain climbing and private planes are a going concern despite being limited to those rich few who can afford them, so too can space tourism develop into a small but successful business model.

Unknown said...

Tony,

Profit motive can be part of vision too, and historically has been in the past. Hate to make a Columbus Reference, but it has to be remembered that the original intent of his expedition was to open up new trade routes to China and India. The colonization of America, likewise, was a hunt for new resources, particularly GOLD. The same is true of the expansion of the American West to a larger and smaller degree.

We speak of "vision" for space exploration, we think of something that exists in space that can be cultivated by humans and turned over for a profit. Helium-3 is the usual space enthusiast McGuffin, and I've heard it theorized that lunar impact craters may possess an abundance of platinum group metals. Gerard O'Neill theorized it would be the exploitation of orbital solar power beamed from space to Earth. In the Star Trek universe, it was the desire of one half-mad scientist to get rich off his warp drive prototype and retire to an island full of naked women.

Governments WILL invest in space exploration if they think the investment will pay off for them nationally. At the moment, the business case for such exploration is more than a little sketchy, so we're not at the "need money for colonies" stage yet. What's needed most is for some of the private space operators to demonstrate the potential profitability of space resources in such a way that the return on investment looks like sure thing and a government can be coaxed funding what appears to be a low-risk, high-gain space project. SpaceX and Orbital Sciences have already demonstrated this model with the Falcon 9: with only modest funding, they've managed to produce both launch vehicles and spacecraft designs capable of reaching and supporting the ISS; where ISS itself is already an established destination for spaceflights, the business case for commercial transport services is now quite solid.

Meanwhile on the horizon we have companies like Deep Space Industries and Planetary Resources LLC that have a vision (there's that word again!) of mining asteroids for rare and valuable materials -- PGMs in particular -- and returning them to Earth. It's plain to see that platinum group metals are valuable enough that even returning small quantities of it can actually turn a spaceflight profitable, and after a few "proof of concept" missions to demonstrate the process, material collection missions might grow over a number of years (decades?) to the point that a key Congressman or two could be convinced that his state/district/constituents could be greatly enriched if only the asteroid miners had Federal funding.

The jump from that to colonization is a bit more complicated, but not that much of a leap. More complicated processes and higher-volume missions might require a longer-term presence by specialists over a matter of months, and year after year as demand for their ores grows, the need for workers also grows, especially since it would quickly become apparent that bulk materials (e.g. platinum ingots smelted out of the ore) would be a lot more valuable than the ore, and that finished products (platinum catalyst beds for PEM fuel cells, maybe?) would be more valuable than bulk products. The first space colonies would be built around those factories.

Damien Sullivan said...

My opinion on Skylon is that I'm unqualified to have an opinion on Skylon.

I support research into alternate launch techniques and on-Earth closed ecosystem stuff. I don't think "building highways" makes sense at the moment.

The thing about human researchers is that while a geologist can do a lot more than a current robot, it's less clear a geologist can do more than 100 robots. The robots hang around longer, too.

"Colonization will not happen as a result of an economic rationale, but rather will become a driving force for one"

Why? People aren't rushing to colonize Namibia or the Yukon or the Gobi.

"where ISS itself is already an established destination for spaceflights, the business case for commercial transport services is now quite solid."

Most of which are paid for by governments as part of a cathedral project. A disposable cathedral, even.

"It's plain to see that platinum group metals are valuable enough that even returning small quantities of it can actually turn a spaceflight profitable"

Platinum is $50,000/kg. 10 tons would be $500 million. I challenge you to return 10 tons of pure platinum from space with $500 million.
If there'd been pure platinum lying naked on the lunar surface it still wouldn't have even scratched the cost of Apollo.

"plain to see" = "I didn't actually do any math".

Elukka said...

Yesterday the Falcon 9 first stage, after separation, turned around and relit three of its engines for a retro burn. Later on it performed a landing burn and attempted to come to a hover above the ocean surface but this failed due to insufficient roll control, causing an engine shutdown that made the rocket hit the surface much harder than planned. This was a test they figured they might as well do since they're flying the rocket anyway, and while it didn't manage a hover, it succesfully performed those parts of the flight profile that had never been tried before - maneuvers and two engine relights as the stage is falling back down.

Separately, landings have been accomplished using a first stage on low altitude flights with the Grasshopper. The pieces are there and next year they hope to do ground landings and if that goes very well, a reuse of a stage.

It seems an odd time to be talking about the inability of rocket technology to evolve.

Damien Sullivan said...

http://www.wired.com/autopia/2013/09/orbital-spacex-sunday/

Orbital Sciences has a contract for 8 deliveries, worth $1.9 billion. The demo dock was 1300 pounds. I get $400,000/kg for commercial deliveries to the ISS.

SpaceX is doing 12 for $1.6 billion, but delivers unspecified less per trip.

Hmm, http://en.wikipedia.org/wiki/Cygnus_%28spacecraft%29 gives higher numbers, and says the contract is for 20 tons overall, bringing it down to $95,000/kg. This is for bulk supplies via unmanned capsule, no lifesupport or human safety rating needed apart from not crashing into the ISS.

Cordwainer said...

Hmm! would hypergolic bi-propellants that can act as mono-propellants(hydrogen peroxide and hydrazine together or apart) or a mixed propellant like MON have some fuel efficiency advantages when used with microrocketry for certain missions like say deep space probes, Tony? I mean micro-rockets would have a great deal of throttle allowing you to maintain low-thrust burns for long periods of time(less thrust than conventional monoprop thrusters) and allowing you high thrust burns when you need them. I would think they would be at least as efficient as crazy ideas like a nuclear powered VASIMR and cost less.

Thucydides said...

Rocket technology is evolving, but to do the wonderful things everyone wants it needs to hit something like the Cambrian explosion.

As Tony keeps pointing out, so long as we use the same sorts of basic technologies as we used at the dawn of the Space age (bipropellant chemical rockets), the laws of physics limits what engineers can do. LH2 + O2 always = 451 second ISP. Unless you can find a way to radically increase ISP (and develop high thrust as well) it is going to be very difficult to get off the Earth using rocket technology. Beamed power using lasers or microwaves may be the way to achieve this, leaving the heavy power generation stuff on the ground and decoupling ISP from the reaction mass (in the atmosphere you are heating air into a plasma). Of course, research for these schemes has been languishing due to the lack of any market for them.

As for SpaceX reusables, I tend to think that they are really going about this the hard way. Long thin boosters will be subject to pretty brutal stresses during re entry, and the mass of the fuel and landing gear will take away from the amount of payload they can carry (key word here being the "pay" in payload). Strapping wings to the booster (like the "Starbooster/Starcore concept) seems simpler to do, but has the same disadvantages in adding mass to the boosters and decreasing the amount of payload you can carry for a given size of rocket.

Thucydides said...

Whoever can find the answer to this question will have hit the jackpot for getting space commercialization and exploration going again:

http://blogs.airspacemag.com/moon/2013/09/the-quest-for-life-elsewhere-rationale-for-a-space-program/

"In science, new findings come all the time and it is highly likely that this “negative” result will soon be countered by some new and compelling “evidence” to the contrary. I think that a long-range strategic rationale to explore and use the Solar System requires re-thinking. A space program needs to return societal value for its cost. I believe that there is abundant value in making our near-term goal the creation of a flexible and permanent system that opens up space for many different and varied uses. Making the space program a Quest for Life Elsewhere is a prescription for failure and ultimately, termination."

Noclevername said...

"Why? People aren't rushing to colonize Namibia or the Yukon or the Gobi."

There's no Gobi Society the way there is a Mars Society or an L5 Society.

The argument goes that having eggs in more than one basket increases the odds of one set of eggs not getting broken when or if the fist basket drops. Sure, some people want to live in space just because it's "cool", others are concerned about the long term and the big picture. I can't speak for all of them, but I've met some and I know they're out there, and they're dedicated.

(As for the Yukon, there are recent increasing trends of people moving to Alaska to "get away from" whatever aspect of society they dislike. Their immigration rate is slowly but steadily growing.)

Noclevername said...

"Rocket technology is evolving, but to do the wonderful things everyone wants it needs to hit something like the Cambrian explosion.

As Tony keeps pointing out, so long as we use the same sorts of basic technologies as we used at the dawn of the Space age (bipropellant chemical rockets), the laws of physics limits what engineers can do. LH2 + O2 always = 451 second ISP. Unless you can find a way to radically increase ISP (and develop high thrust as well) it is going to be very difficult to get off the Earth using rocket technology."

I fuel costs were the only or even the main barrier, the costs of launches would be a fraction of what they are now. It's considerations like a huge ground crew and the manufacture of custom single-use parts by politically chosen contractors that drive up the cost.

Noclevername said...

"A space program needs to return societal value for its cost. I believe that there is abundant value in making our near-term goal the creation of a flexible and permanent system that opens up space for many different and varied uses. "

I couldn't agree more. Colonization will happen only as part of a greater presence and infrastructure in space.

Noclevername said...

Also let me clear up some confusion: I'm not just talking about launching technologies, but space drives as well. The future there is less predictable but more open-ended, as things like magsails and electric or thermal/electric drives are yet to bear fruit.

ISRU and increasingly flexible automated fabrication will likely also reduce the amount of materials needed to launch from Earth.

Cordwainer said...

Well,Thucydides solar thermal could get good Isp and high thrust and could be couple with beamed power later once you get enough of the requisite infrastructure in space. If the Earth were to run into a real energy crisis then space based beamed power platforms might become necessary, thus encouraging the creation of requisite beamed power propulsion technology. Problem is I think Nuclear Fission will be able to provide the requisite energy we need if such an energy crisis were to occur and their are other space launch alternatives that could work as well and be more applicable to heavy lift and more energy efficient than beamed propulsion.

People aren't rushing to colonize Namibia because the government is unstable, immigration is increasing and has been pretty dramatic in the past for Namibia's neighbors like Angola and South Africa. If Global warming continues the Yukon might be a paradise. Historically the Gobi was a great crossroads and became the desert it is due in part to human agriculture, China has spent billions to irrigate the Western half of the Gobi and part of the Purple Revolution was forced immigration of dissidents to farm that remote region. That being said colonizing space is full of costs and rigors and lack of profit motive that would make the Age of Discovery mariners cringe.

I do wonder if a mobile attachable kick motor using micro-rockets might solve some of the issues with restart burns and fuel efficiency over Tony's idea of a dockable stage. It could act as a "space pickup truck" to push satellites to higher orbit within the same orbital plane, thus reducing the need for satellites to carry their own kick motors. Satellites could then use electric propulsion units for minor attitude station-keeping maneuvers. Conventional dockable stages would be better suited to pushing satellites from one orbital plane to another, but Oops! that wouldn't be that profitable unless you use modular satellites since there isn't much call for that in the commercial satellite sector.

Damien Sullivan said...

"Even if you finally do find martian microbes, what have you proven?"

*headdesk* You start learning about life's diversity, history, or both? If they're Earthlike, that raises one set of questions. If they're like nothing here, then you start exploring a truly alien ecosystem.

"I believe that there is abundant value in making our near-term goal the creation of a flexible and permanent system that opens up space for many different and varied uses."

And having stated this belief, the author will now sign off without trying to support his belief.

Damien Sullivan said...

"There's no Gobi Society the way there is a Mars Society or an L5 Society."

Sure, there's a dream of "SPAAACE". I've had it myself. But dreams are cheap. New worlds aren't settled for dreams, they're settled for someone's profit.

"The argument goes that having eggs in more than one basket increases the odds of one set of eggs not getting broken when or if the fist basket drops"

That's a common argument, yes. But it's not very convincing. People care a lot more about their own survival than humanity's, and despite that we don't even do much to harden our own basket, despite this being much cheaper than throwing eggs elsewhere.

"People aren't rushing to colonize Namibia because the government is unstable"

Actually it's pretty stable near as I can tell. Hasn't really been tested by SWAPO losing an election yet but still. People don't rush to colonize Namibia because it's really dry and has nothing to draw people other than cheap empty land, lots of sunlight, and lots of valuable minerals. I.e. just like space, but much cheaper and easier due to free oxygen and radiation shielding.

Noclevername said...

"Sure, there's a dream of "SPAAACE". I've had it myself. But dreams are cheap. New worlds aren't settled for dreams, they're settled for someone's profit."

A bad analogy to European colonization. Different time, different economy, different technology, different environment. Space settlement is an entirely seperate matter, and one with no historical precedent. Despite calling the Americas the "New World", we have zero experience with actually settling other worlds.

As I previously pointed out, there's profit to be made in transporting "dreamers" and all their stuff. It will not be the main source of space-based revenue, true. It is not something that can be done or even started today. But it will become a possibility once a mature space infrastructure is established. We can start laying the foundations now through research and experiment.

Brett said...

@Noclevername
As I previously pointed out, there's profit to be made in transporting "dreamers" and all their stuff.

It's going to have to be the dreamers who pay for the colony and launches, even if the testing is done with government spending. Like I said, I think that's certainly a possibility if society continues to grow richer overall. It took the Spanish Crown to fund a three ship expedition to the Americas in 1492 (plus the follow-up expeditions/invasions), but by 1620 a group of wealthy investors and about 800 Puritans was able to send an 11-ship, 800-person fleet to New England to successfully found a colony.

What's weird is that theoretically a colony could pay for itself even without sending anything physical back to Earth. The increasingly digital economy opens the door for digital goods and services that let you do that, although I doubt it would ever be the primary reason for launching the expedition. Mining heavy metals alone is not going to pay the upfront costs necessary to get the infrastructure in space to make space mining profitable (hence why Planetary Resources is trying "steps" to get there, like selling telescope time).

. . . I hate it too when space colonization advocates compare it to settling the New World. They're nothing alike - the Spanish made big gains from the second expedition, and the British who were trying to duplicate that in North America found a source of profit that was generating 1000% returns if the colonial conditions didn't kill you along with 85-90% of the rest of the new arrivals in the first year (tobacco). There's nothing like that in space - not platinum metals, nor Helium-3 unless someone gets a working, cost-effective fusion reactor going (and even then, you have to compare it with the opportunity costs of alternative power sources).

Thucydides said...

"I fuel costs were the only or even the main barrier, the costs of launches would be a fraction of what they are now. It's considerations like a huge ground crew and the manufacture of custom single-use parts by politically chosen contractors that drive up the cost."

It isn't the cost of the fuel, or even the cost of the technology (really). No matter what you do, no matter how much or little you pay, the laws of physics are enforced always and everywhere: You will NEVER get more that 451 seconds ISP from a LH2 + O2 rocket motor (and if you screw up you can end up with less). This is the point that Tony is trying to make (and I reluctantly agree with). A carbon fiber fuselage and a motor made in a 3D printer out of diamond may give you somewhat more performance than a rocket made of metal, but not the fundamental leap that marked the transition from steam to internal combustion, for example.

I am intrigued by the idea of beamed power simply because so much of the Rocket Equation is driven by mass. The Space Shuttle launch stack weighed about 2000 tons, with the bulk of that being the fuel and oxidizer. Most of the fuel and oxidizer was needed to lift the rest of the fuel and oxidizer...

A laser rocket can use atmospheric air for much of the flight, and a small tank of Hydrogen (or water, for that matter) for the final push into orbit. Of course this is a rocket driven by a big honking laser (or more likely a laser battery with dozens of ground based lasers sending a beam through a single tracking mirror). While I don't have Liek Myrabo's book handy, I seem to recall that the amount of remass for a Space Shuttle sized vehicle propelled this way could be measured in tens of tons rather than thousands.

Tony said...

1. Microrockets can't be all things to all people. They have an optimum operating pressure for maximum efficiency. With the claimed 1000:1 thrust to weight ratio at maximum power, I'm willing to bet they have Isps in the double digits when they're run at significantly lower thrust. There just has to be too much specialized design for the top end of the performance spectrum for such systems to work with any kind of efficiency at all outside of a very narrow band of performance.

2. Politics and cost. Way, way waaaayyy oversold as a factor in the cost of launch services. THings cost what they do because they're actually that expensive. As pointed out previously, COTS contracts to SpaceX and Orbital Sciences are setting record high per kilogram costs for mass on-orbit. While it's true that those are total costs including the development and manufacture of a dockable, pressurized orbital delivery vehicle, COTS is not setting any records for cheap launch services.

Also, SpaceX flew their first several flights in angel investor startup mode. After that they've lived off of the government tit, just like Boeing and LockMart. Anything you read about SpaceX doing things cheaper is pure hype.

There's just no way to reduce launch costs all that much, simply because space launch costs what it does for good reasons, not just bureaucratic fiat.

Anonymous said...

Research outposts, like the ones we maintain in remote areas like Antarctica, seem to be a resonable first step in off-world infrastructure. The ISS is curently our only example of an off-world research outpost, but it is a start. It does seem reasonable that more of these outposts would result in more space launches, simply to suport them. Profit motive for research outposts is secondary; people back home will use the research gathered to their own purposes...like always. While I am not as pesimistic about the time needed to develop a permanent population living off-world being several centuries, I also don't think it will come in my lifetime, but I'm willing to bet it will in my granddaughter's.
One thing is certain, however; none of use can foresee what will happen in the next few years, and certainly not the next few decades. People are contenually being surprised by the future, being both delighted and disapointed by it. Just like always.

Ferrell

Damien Sullivan said...

"space launch costs what it does for good reasons"

What *are* those reasons? I mean, what's the breakdown? The cost of the fuel? The cost of the raw material of a disposable rocket? The labor/capital cost of making a rocket? The cost of a satellite payload? The first and second are bounded by the physics of using chemical rockets and the general prices of energy and metals. The third and fourth seem potentially more flexible.

Damien Sullivan said...

http://forum.nasaspaceflight.com/index.php?topic=19363.0
"Both 747s and (expendable) rockets cost about $500 per kilogram of dry
mass"

A new 747-8 costs $350 million; Wikipedia seems to say it can carry 230 tonnes. If you throw the plane away after one use, that comes to $1521/kg. Hey, that's in the order of LEO costs.

Passenger capacity about 600, so that's $500,000/passenger, way less than the $20 million Russia charges, but still leaving space in the "toy for very rich people" category.

The Epsilon rocket implies that using automation to reduce a ground crew of 150 to 8 drops the rocket price in half. Nice, but not the orders of magnitude we'd want... And Wikipedia says it in fact is smaller than and doesn't launch as much as the rocket it's replacing. Launches 1200 kg instead of 1800 kg in 3-stage configuration. So payload cost actually goes down by 25%, I'm guessing. Epsilon's also using a solid first stage.

So even mostly wiping out launch crew labor doesn't get you that much. "We're building an airplane and throwing it away" seems to dominate.

...also at $38 million and 1200 kg, that's $32,000/kg to LEO. Way more than throwing away a 747, actually...

Cordwainer said...

I agree with Tony that we probably won't see any big improvements in rocketry and propulsion within our lifetimes but I'm not sold on the idea that we won't see small incremental improvements. After all we have seen a great deal of advancements in combustion engines over the last century and like rockets they are quite limited in their efficiency and design parameters due to major physical constraints. Similarly we have seen quite a lot of advancement in Satellite and network communications over the years so I don't think applying similar ideas towards portability and modularity that have been applied to ground infrastructure to infrastructure in space is completely beyond the pale.

I also don't see space tourism expanding exponentially any time soon. Though you could see Space Hotels for the very rich sometime in the near future. Leasing space on such habitats for observatories and scientific experiments and studies could be used to bring the costs down to within reasonable limits for the top 10 to top 20 percentile of income.

I'm not all that certain you couldn't design micro-rocket propulsion units with a great deal of flexibility. After all you could have an array of thrusters with different bands of performance. Typically an individual thruster puts out between 5 to 9 newtons(MIT has been trying to get that individual output up to between 12 and 15 units) and theoretically arrays could be built to produce up to 500newtons using current liquid oxygen and ethanol propellant micro-thrusters. They have also been experimenting with hydrazine micro-thrusters that can produce thrust in even smaller orders of magnitude. Since manufacture is via MIM processes their manufacture could be cheap and might offer better surface wedding of the propulsion unit to a vehicles frame or fuselage.

Damien Sullivan said...

So, I'm reminded that the US *has* a working spaceplane of sorts, the X-37, currently doing extended mysterious missions for the Air Force. Wikipedia says alleged mission goals include refuelling and solar panel repair, plus 3 km/s of in-orbit delta-vee. It's been observed in March raising its orbit 29 miles to 248 miles up.

Takes off strapped to a rocket like the other orbital spaceplanes, of course. Elon Musk claims first stage is 3/4 of the cost of launches, so we're still looking for the (cheaply, rapidly) reusable first stage holy grail.

But yeah. The US has *two* space programs.

Cordwainer said...

Also given that we will only tend to see more and more expendable payloads in the future. (Although I'm not all that certain that will continue to be the case for expendable launchers) We very well could see a business model for removal of at least the most dangerous space junk, similar to teams of space junk salvage crews like in the anime Planetes. If the risks of such debris become bad enough then you could see plenty of funding from different sources both governmental, satellite dependent business, space entrepeneurs and those business that bankroll and insure the aforementioned business.

As to near term technologies that could improve Isp and Thrust just for shits and giggles lets dicuss the top contenders their cost effectiveness and feasibility, maybe.

1. Beamed propulsion to include beamed power.

2. Laser Thermal propulsion both beamed and onboard systems or a hybrid of both.

3. Magneto-hydrodynamic systems like VASIMR and Helicon Injected Inertial Plasma Electrostatic Rockets(the leaky assymetrical Inertial Electrostatic Confinement grid variety not to be confused with HiPEP)

4. Solar-Thermal

5. MIM manufactured micro-thrusters.

6. Sails and tethers.

7. Mass drivers and Meso-particle drivers.

Personally I'm laying my bets on micro-thrusters, solar thermal and meso-particle drivers as the most useful in the near term.

Cordwainer said...

That was invitation for others to discuss I'll take leave of the floor now to watch anime and play video games. I think I've contributed enough for awhile now I would like to see everyone's thoughts on such technology. Obviously we can't improve ground launch capability too much but it seem reasonable we could make a number of advancements using the aforementioned methods to improve LEO, cislunar and deep space flight.

Cordwainer said...

Yeah, I heard the X-37 is rumored to be based off an unmanned version of the Russian Buran Space Shuttle concept. Well I did say Evolved Delta wouldn't be that much more expensive for governments to fund if their is a perceived need for it. Even if it isn't really as efficient as Tony says. Hearkens back to the "what are people really willing to pay for space infrastructure", argument.

Brett said...

@Thucydides

I like the Laser Propulsion idea, and they've done some interesting little pre-tests on it. The wikipedia article on beam-powered propulsion includes a test they did in 2000, where they lifted a 1.8 oz, 12-cm-wide rocket 233 feet into the air for about 13 seconds. It doesn't say how powerful the laser was, although it's implied that the power output was significantly lower than 100 kilowatts.

The power output for something that could lift the 70-130 metric tons to LEO that SLS might someday do would be heroic. You'd probably have to do it the "ablative" or "heat up the atmosphere"/Myrabo way, since the actual momentum of photons is pretty weak - it takes something like 300 MW to accelerate one kilogram at one meter/second^2. Not sure how much it would ultimately take, but it would have the advantage of front-loading more stuff down here on Earth (and being a potentially formidable ground-to-space weapon).

Damien Sullivan said...

I do wonder why launch from airplane isn't used more. It seems the obvious thing, but since almost no one does it clearly there's a problem. It *is* done: the Pegasus is an air-launched orbital rocket, but that's really expensive, not cheap, so not a royal road to cheapness after all. Advantage seems to be orbital flexibility for small payloads, not cost. Plane size would be a limit[1], but Pegasus has used a Stratofortress and a L-1011 as first stage, large but not 747 large.

[1] We've seen a Shuttle being carried on a 747. Now imagine a Shuttle+main tank being so carried...

Cordwainer said...

The double-pulse ablative way would probably be the only one that could provide sufficient thrust for lifting a reasonable payload and the onboard laser would lower your payload margin somewhat.

The X-37 does bring up the power of politics in space though. If things continue to heat up between China and the U.S. over the Koreas and other international affairs one could very well see China investing more both in modernizing their military and in both public and clandestine space programs. Modernizing their Air Force, building more aircraft carriers and using space as a draw to get young kids into the pilot seat or join the signal corps through the inclusion of sholarships for space sciences might be the panacea for the feminization of men syndrome they've been dealing with and a way to beef up their armed forces. Yeah, I know there military is mostly draftee or lottery based but they still need a way to get people to stay after their initial term and study those modern long term skills they really need.

In turn you could see a lot more manned missions from China, and if their is anyone positioned enough for a significant population push/need for new resources draw to outer space it would be a consortium of China, India and North Korea. A misguided out-of-proportion perception of need for such projects due to lack of resources and physical space, and the very real threat of the political powers that be to limit any territorial expansion as well as China's historical lack of interest in such expansion might be used to advance even the impossibly expensive idea of a space colony or lunar colony. Of course reclaiming land areable land from the Ghobi or the seacoast would be less expensive. Who's to say though? Governments and people in general often act irrationally.

Damien Sullivan said...

Hmm, I see people are pursuing the air launch approach, anyway. Including Stratolaunch/Pegasus II, aiming for 6 tonnes to LEO, from the world's longest wingspan craft, made from two cannibalized 747s... 4 stage option for 2 tonnes to GTO, probably under a tonne to GEO.

Hmm, a loaded X-37B is just under 5 tonnes. Wonder if you could combine the two for a fully reusable[1] system.

[1] Well, depending on how much an X-37 needs to be rebuilt.

Cordwainer said...

Seems likely that you could either increase the size of payloads for aerial launch by a reasonable although not considerable amount. Space Ship 2 and 3 for example.

You might also be able to increase the speed and or altitude of aerial launches for small payloads as well, thus contributing to delta v or fuel efficiency. I believe Centaur uses such a strategy.

Cordwainer said...

Like the idea of a fully reusable system with an air launched spaceplane, Damien. That might just be doable I wonder what Tony would have to say on that subject. How far can the X37-B be placed into LEO, I don't think you could get insert that 5 tonnes quite as far and save as much fuel though from a typical air launch compared to a expendable first stage. You could make the first stage recoverable or design a fast high altitude air launch platform, or just a more massive high altitude launch plane capable of carrying more tonnage. I'm guessing their would be limits on payload carrying capacity probably some where around 8 to 10 tonnes.

Damien Sullivan said...

I'm guessing that a supersonic carrier with big extrusions is "haha no" and the main benefit is from climbing above as much atmosphere as possible. (WP says launch vehicles in general stay subsonic below 30 km to reduce drag.) That said, Pegasus II seems to be aiming for launch from 9 km, vs. the 12 km of Pegasus. Odd.

X-37 uses Atlas V and Centaur for launch; couldn't just plop that onto a Stratolaunch without reworking. And hmm, I take my fully reusable idea back: what would be reusable would be the "first stage" (Stratolaunch) and the space stage (spaceplane). The intermediate stages pushing the spaceplane to orbit from 9 km would still be disposable rockets.

Still a big cost saving, if Elon Musk is right. Which maybe he isn't.

Cordwainer said...

Forgot to mention Imploding Plasma Liner Fusion Propulsion for high Isp and High thrust technologies. I didn't want to turn this into a advance propulsion blog since that isn't exactly what I call near-term even if the liner approach turns out to be plausible. Seems like Mini-Mag Orion or a Dusty Plasma Fission Fragment Rocket or other fission fragment propulsion concept would be easier to design and build in my opinion.

Cordwainer said...

Maybe Pegasus II is launching from 9km to test the drag forces for a future scramjet stage, unlikely though.

Tony said...

Don't know quite hat to say at this point. Things going all over the place...

Launch vehicle hardware isn't the big cost item. Launch campaigns for Delta and Atlas seem to be about $10M per ton to LEO right now. It's kind of hard to tell what the launch services portion of Falcon 9 launches are, because of the omnibus nature of the SpaceX COTS contracts. But the hardware itself can't cost more than a few tens of millions per example.

Also -- and for some reason people seem to keep forgetting this -- the launch vehicle hardware is, for cost accounting purposes, just a consumable item, like propellant. The launch services companies aren't selling rockets. They're selling rides on whatever vehicle they choose to use.

Yes, I know that's an oversimplification in several ways. Spacecraft have to be designed to interface with a given launch vehicle configuration. The launch services customers do know what vehicle their spacecraft is going to ride on, to the point that no two launch vehicles have ever been configured exactly alike (not even for Shuttle missions). Customers are sometimes loyal to one launch services provider over the others, for whatever reason they may be. But for accounting purposes, the launch vehicle is not a thing the customer is purchasing. The ride to orbit is what they are buying.

So, what is all of that supposed to mean? Well...launch services companies are in business to make a profit. Rockets aren't capital equipment, to be sold on their own merits. Customers don't want to spend more than they need to for launch services, even if the market isn't very broad in terms of competitive suppliers. Those three factors, put together, suggest to me that hardware for space launch is not sold at inflated prices. It costs what it costs.

I think I should also remind people (again) that the cost of operating in space is really what eats into space operations budgets, government or private. It turns out that, in dollar terms, LEO isn't "halfway to anywhere". It's more like 10-20% of the way. If launch services were without any cost whatsoever, project budgets would still be hundreds of millions or billions of dollars. That is why cheaper launch services won't attract more than marginal traffic increases.

Cordwainer said...

Question, Tony so does that mean if a specific type of payload or space infrastructure is preferred over another for whatever perceived reason that the investment dollars to create such infrastructure might be put into it. Not grand vision programs for depoting, modularity, space tugs or evolved delta but small scale programs tailored to specific buyers for specific missions. Whether a perceived cost incentive is there or not for such programs is somewhat irrelevant, people act irrationally with their investments all the time. Also for specific missions different technologies might offer advantages to certain operation cost in space or here on Earth.(and not just in the launcher capability but also in the capabilities of payloads)

Thucydides said...

Cord

Most of the examples you give are for deep space propulsion, not blasting through the atmosphere and achieving orbit.

A XKCD cartoon some time ago made the point. Getting to space was rather easy (100km; yaaaay!); staying in space is difficult (darn). A suborbital rocket that can get you past the 100km mark is 1940 era technology, and it is theoretically possible to strap a solid fuel booster on a high performance jet fighter and do a zoom climb and coast past the 100km mark. (Getting back will require some pretty hair raising flying on the part of the aircrew).

None of these feats puts the vehicle at 100km with enough velocity to stay in orbit, you need a hell of a lot more energy. Compare a German A-4 (aka V-2) against the Soviet R-7:

A-4
Weight 12,500 kg (27,600 lb)
Length 14 m (45 ft 11 in)
Diameter 1.65 m (5 ft 5 in)

R-7
Weight 280 metric tons (280 long tons; 310 short tons)
Length 34 m (112 ft)
Diameter 3.02 m (9.9 ft)

Now laser of microwave thermal (like Liek Myrabo's system) leave most of the 280 metric tons on the ground in the form of generators, lasers and mirrors, but the air or ablative materials are still receiving mega or gigawatts of energy. A mass driver capable of flinging a payload into orbit is essentially launching a meteor upwards at 7.8 Km/s (and this is true for rail guns or light gas guns as well.)

As for the other question of what impells people to move; freedom from persecution is a big driver, and the search for better jobs and opportunity is another. People go to Alaska to get away from having people and governments in your face all the time, or for a good job (or both), more people migrate to Texas IOT get a good job. Plenty of room in Space to keep clear of people you don't like, unless it is the other crew member, but not so many high paying jobs or free tracts of farmland and virgin timber out there....

Tony said...

People who make irrational investments don't build anything lasting. I don't think we want to invest much time discussing that type of thing.

If we're talking aboout investments in rationally defensible space operations, bring a big checkbook. The applicable technologies just aren't mass-producible for the size of the market, and there are no plausible market expanders that I've yet heard of -- certainly nothing mentioned here.

Cordwainer said...

Mega-watts and Giga-watts of power with the low efficiencies of lasers. Sounds dangerous and expensive, might be sound for boosting unmanned payloads which are the majority though. As Tony points out though most of the cost is in space operations once you get something into orbit, which is why I brought up the discussion of deep space or orbital propulsion systems for when you get your payload in orbit.

I would point out that irrational investors and dreamy-eyed entrepeneurs do build things that last, they just do it by accident or coincidence as part of their many grandiose ideas. In other words there plans may not live up to there expectations or be profitable for them but they often leave behind advancements that do turn out to be useful and profitable for others later on.

At this point I'm through trying to come up with possible ideas for future expandability of the space market either there not there as Tony says, he's dead wrong or they haven't been invented yet. I guess I'm not that creative, kinda makes things boring though. Final question Tony what would the applicable technologies to make space operations cheaper be and what would it take to make them mass producible. Nanotechnology? Large scale 3D or MIM machining processes? Advanced robotics? Dirt cheap power? Some combination of the science fictiony elements mentioned above.

Rick said...

Welcome to a returning commenter!

I do ask 'anonymous' commenters to sign a name or handle, to make it easier to follow the conversation.


My opinion on Skylon is that I'm unqualified to have an opinion on Skylon.

That makes at least two of us - and this is one of the wiser comments ever made on this board.


I did see the Falcon 9 / CASSIOPE launch - thanks to Elukka for explaining what I observed after staging. I could tell that *something* was going on with the first stage.

I remain doubtful that recovering the stage will actually turn out to be a money saver, but I'm happy to see SpaceX experiment with it! After all, I could easily be wrong, per the above quote about Skylon.


'Waste, fraud, and abuse' in government spending is an ever-popular target for grandstanding, but it is hugely overhyped.

As some commenters have said, the big money is in policy choices. A relevant - if hypothetical - is the 'rocket a day' idea of subsidizing expanded launch capacity in hope that the traffic demand will follow.

I would love that to happen - but for people who don't care much about space it would look like a colossal boondoggle, a prime example of 'waste, fraud, and abuse.' And since most of the public doesn't care that much about space, it almost certainly won't happen.


This thread is up to 122 comments, so not exactly sluggish!

And I do plan to have another front page post up 'soon' - at any rate, much sooner than the last one!

Anonymous said...

I think eventually advanced robotics and additive manufacturing, such as 3D printing, will lead to building structures in space using materials from either the Moon or asteroids. The more the robotic factories can crank out, the less that will have to ride uphill on rockets.

Eventually, we would only have to take astronauts, advanced electronics, and food. Of course, it could take decades before that kind of space infrastructure would be possible. Maybe your grandchildren will see it.

Ron

Thucydides said...

Cord

I'm getting one of those "chicken and egg" moments reading your post, maybe I'm not tracking what you are trying to say.

WRT advanced deep space propulsion systems, I'm not sure they are the answer either, although they might be part of the answer. If space operations cost "x"/day, then obviously a fusion rocket that can get you to Mars in >90 days will provide a big cost savings on the operations side compared to a chemical rocket that takes 180 days just to get there. Of course your time on Mars should not be cut short just to save a few bucks, and the return leg using a fast rocket can save more time and operational money. So a fusion rocket saves six months of operations costs for mission control, ground tracking etc. (90 days there + 90 days back vs 180 days there + 180 days back using chemical rockets)

OTOH, we already know how to build chemical rockets that can get to Mars (the Saturn 5, and various hypothetical rockets made from Space Shuttle technology, as well as proposed SpaceX products like the Falcon 9 heavy or Falcon X can all put large payloads on trajectories to Mars), while we don't even have working models of a fusion rocket, or VASMIR scaled to the right size, or a large enough solar sail.....All potentially workable technologies, but all that need considerable R&D before we can put them into orbit using a big a**ed chemical rocket.

Since mass production isn't in the cards (except maybe for military space systems), what we should be looking at is low cost manufacturing systems like 3D printing, which allows you to build custom and small production run items quickly and cheaply.

Of course this is a relative term as well; since a proper spacecraft is about the size of an airliner, the assembly hall/3D printer will have to be correspondingly large if you want to make most of the stack that way.

Cordwainer said...

What I was trying to do was steer the conversation away from discussions on big a**ed chemical rockets and launch mechanisms, because I merely figured enough had been said on the subject and Tony is right that the majority of costs are actually in space operations and not necessarily the cost of getting there. One could probably bring the costs of launchers down by a slight margin but not enough to justify a launch a day or massive space infrastructure improvements.

Improvements in orbital and deep space propulsion would be just one area among others that have been mentioned that could help to lower operation costs as well as increase capabilities for commercial use of outer space. I was merely listing possible ways that incremental near term improvements might effect how we use outer space commercially.

Obviously though the consensus is that due to the enormous cost of space travel and space operations and the physics involved that no amount of incremental changes would create a sea change towards improved infrastructure for the exploitation of space for profit.
What we have now is good enough and will probably remain largely unchanged in the future. We will continue to have expendable rockets and satellites that are designed for a specific role that is non-negotiable and non-upgradeable and results in them slowly decaying into less and less useful machines throughout there life times. Weep not for the satellite, because we can always throw another one up there even though that means even more space junk we have to burn up in the atmosphere. Increasing the capabilities of what we send up there over time, increase shelf life, keep the space lanes clear of clutter and junk. Why would we want sustainability in space that's for the tree-hugging hippies here on Earth.

Let's face it short of dirt cheap energy and dirt cheap production methods humans or even are robotic servants are never getting of this rock in any large numbers and that's that. I think I'll stick to science fiction that puts humans in floating cities or under the deep blue sea, at least that seems more probable. There really isn't much for us to do "out there" that are machines can't do for us, anyways.

Geoffrey S H said...

Ironic isn't it? We set out to construct a more accurate view of space and space-based civilisations that star wars and star trek couldn't do, we accepted how realistic spacecraft could look, and we have come so far on realism we have backed ourselves into a corner and cannot get out, thus making even the most accurate spacecraft a total fantasy.

And floating cities and deep sea colonies are just as fanciful due to the pressure of the water and limited access to resources.

So that's it. Hard science fiction is a mirage. Stick to science fantasy. I'm just glad I have a job unconnected with a need to write sci-fi.

Damien Sullivan said...

"Hard science fiction is a mirage"

Not at all. "Frontier" hard science fiction, with Space! or Ocean colonies! may be a mirage. There's still lots of interesting futures possible, from some sort of Singularity through transhumanism and cyberpunk to WWIII. Possible future issues include:

* longevity
* growing automation
* full AI
* genome mastery and genetic engineering
* exowombs
* peak oil
* global warming
* unsustainable agriculture
* the surveillance state
* brain mastery, a world beyond Ritalin and Modafinil, lie detectors that work
* war, with drones and EMPs
* nuclear terrorism
* the failure of all antibiotics, or new plague viruses
* the fate and enforcement of intellectual property in a world of easy duplication

etc.
Stross just asked "what are the geopolitical effects of driverless cars?", most of the answers I saw were sociological instead, but it's still an interesting question.

It'd be nice if the most likely future is a cozy Clarke utopia like _The Deep Range_ or _Imperial Earth_ (where the space bit arguably exists to justify an adult wandering Earth like a newb), but it's hardly certain. We could get the Instrumentality of Mankind, or the World State, or WWIII, or "AI the movie" instead. Alastair Reynolds' Demarchists and Conjoiners could exist right here on Earth, as could Joan Vinge's Demarchists. Or the dystopian Kazakhstan from GURPS Transhuman Space -- and THS in general has a range of futures in a diverse world, even without the space bits.

And in lots of ways space would be easier for infomorphs. Want space? Learn to identify with your AI cousins...

jollyreaper said...


So that's it. Hard science fiction is a mirage. Stick to science fantasy. I'm just glad I have a job unconnected with a need to write sci-fi.


That's pretty much where I'm at. It's hard to do right, that's why they call it hard SF. So what I really look for is internal consistency and secondary effects.

Even at that, you'll have plenty of WTF moments in fantasy, the sciency and wizardy kind both. Just like the Star Trek transporter should change everything and is just blithely used as a transportation technology, you'll find plenty of straight-up magic that should change the world but doesn't.

From Harry Potter. Imagine the implications of polyjuice potions in espionage. Or universal truth serums. Or the time-turner. You can muck with time?! And you're just using it to cram for tests or save a hippogriff? What about changing the outcome of battles! You have the makings of a proper Time War on your hands.

In competent hands, you could have some real fun with how resolutely backwards the wizard world is, like the Chinese having the makings of a world empire and the Confucians preventing that kind of upheaval. Fireworks but no guns, treasure ships that are abandoned, turning inwards.

jollyreaper said...

Not at all. "Frontier" hard science fiction, with Space! or Ocean colonies! may be a mirage. There's still lots of interesting futures possible, from some sort of Singularity through transhumanism and cyberpunk to WWIII.

Ok, to refine the statement, hard space opera ain't happening. But everything you mentioned is pretty much near-future on Earth. Rocketpunk just isn't possible, you need too much fantasy tech to make it work. Le sigh.

Anonymous said...

Jollyreaper wrote, "Ok, to refine the statement, hard space opera ain't happening. But everything you mentioned is pretty much near-future on Earth. Rocketpunk just isn't possible, you need too much fantasy tech to make it work. Le sigh."

You only need a little magitech to make it work.

Limited anti-gravity that has to push off a fairly strong gravitational field would get you to orbit for cheap, but not to other planets. Torch drives for interplanetary use are not too far of a stretch. For space opera stories you add an FTL drive with some hand waving.

You only have to gloss over the propulsion systems you use. Everything else can still be realistic.

Of course, that will work for your sci-fi novel, but not in the real world. Unless there is something science has missed, we're stuck down here.

Then again, Earth is a pretty nice place.

Ron

Damien Sullivan said...

"But everything you mentioned is pretty much near-future on Earth"

No, the "automation increasing now" and environmental crises are near-future. Nothing stops you from trying to imagine Earth 500 years from now, or 1500, or 50,000. Post-immortality, or post-AI, or whatever. There shouldn't be any reason why the 23rd century is easier to write stories about in space than on Earth, and there's plenty of changes that could happen on Earth by then, as I listed.

Brett said...

@Geoffrey S H

Floating cities aren't really fanciful, since you could build one in the near-future just by lashing a bunch of boats together. They're just politically difficult - the only reason you'd found one is because you want to do stuff there that may not be kosher back in existing nation-states, and it had better be profitable enough so that it can pay for the importation of goods and services. I've always figured the best reason for building one would be to take advantage of potential research talent when visas for researchers in a particular country are in short supply, but so far they aren't.

Undersea cities just don't make sense at all, unfortunately.

@Damien Sullivan

True, I think it's more a particular variety of SF is on tricky grounds. Your best bet if you want to write those kinds of space opera stories anyways is to do what James A Corey did with the recent Expanse series of books: avoid specific dates on a timeline from now, include realistic elements but don't be too realistic (and be open about that in interviews), and just enjoy the ride.

We might be able to do more than just identify with our space robot cousins. Down the line, maybe we could take the information and experiences they had, convert it into something we could experience virtually, and then it experience it here. Or even go better and actually create the impression that we had such an experience, like how we can stimulate the creation of false memories now.

Of course, if you've got that kind of crazy good robotics and AI, you might be the type of society that would laugh at the cost of space launches, and have plenty of space infrastructure anyways. Just think about how much of an collaborative societal effort it took the ancient Egyptians to build a near-solid pyramid of limestone and granite, something that would be vastly easier today simply because it's a far smaller expense compared to the overall economy.

@jollyreaper

I loved the books, but the Harry Potter Universe definitely does not make sense. Imagine how incredibly useful magic would have been before everyone supposedly went secret: cures for tons of stuff, nearly instantaneous communication across vast distances, and so forth. And that would be going on for centuries before the separation, which is why I think it wouldn't happen - such a world would just be unrecognizable to our own, with a far different history.

It's the same problem with a lot of urban fantasy and comic book stories. They want to keep the implicit "Real World Plus X" setting, even when the "X" would make the "Real World" unrecognizable if the people there actually acted like real people.



jollyreaper said...

The advantage with urban fantasy is there's less world-building with "real world plus x." But you are right about the ignoring of second order effects. It feels like laziness for the most part. You can get a freebie by making the point of divergence be right now, like zombies didn't exist until the first outbreak yesterday. But at that point, everything becomes different.

There was a very frustrating trilogy in the zombie genre recently, Newsflesh. 30 years after the Rising, civilization has held the zombies at bay, bloggers have become the most trusted source in news since they were far better than the MSM during the Rising, etc. First novel did a good job of exploring a near-future world with people holed up in their fortified towns and cities, avoiding large gatherings, constant blood testing to see if someone might be going zombie. Bloggers are divided into Stewarts who do hard news and Irwins who do stupid shit for ratings.

So they start with this promising premise and just turn into irredeemable crap. Big government conspiracies, mustache-twirling villains, going from mentioning that cloning tech exists to successfully resurrecting the dead with memories intact,and tons and tons of needless padding. It makes me so angry that I read the damn thing to the end. It wasn't worth it.

Point is, the story gave the illusion of trying to think through the implications of the world and was very interesting to start with and then became a bleeding, rotting pile of shambling shit.

Anonymous said...

jollyreaper, many times,in my opinion, writters sometimes have a wonderful idea, but they "run out of steam" before they get through the first half of the novel, but go ahead and write the triligy anyway. Just remember Sturgon's Law..."90% of anything is crap"! And I do know that feeling you get when you get to the end of a book and then wonder why you read it in the first place. So frustrating that so many can't follow through on an intersting idea.

Ferrell

Damien Sullivan said...

"ashing a bunch of boats together. They're just politically difficult - the only reason you'd found one is because you want to do stuff there that may not be kosher "

Or because you're running out of desirable land. Hong Kong, Singapore, Japan, the Netherlands, and drowning island nations seem decent candidates for such a strategy. Thing is it needs to be cheaper/better than landfill or reclamation. But with rising sea levels, it might become so... esp. if someone developed something that was cheap and resistant to seawater corrosion.

"Harry Potter and the Methods of Rationality" is famous as a fanfic which takes the piss out of the HP universe. Also serves as a platform for the author's pet ideas.

The Anita Blake books started with the premise that supernaturals had recently come out into the open and gotten legal rights, that was an interesting premise. At the other end, Robin McKinley's Sunshine takes place in an alternate universe where magic has *always* been out in the open. History should be different? It is! We hear mention of the Liberty Wars between us and Albion, and the global council, and globenet. How different? We don't know, the narrator is a hyperfocused restaurant worker who doesn't care about history, and it's never even clear to the reader who won those Liberty Wars. Not a sustainable approach, but it's a great book.

Cordwainer said...

I was being sarcastic with the floating cities and deep blue sea remark.

That being said I think that full scale mining efforts or the sea-bed along continental shelfs wouldn't be that hard to with near-term future technology. Underwater projects would be mostly handled by automatons but humans would still have to handle and manage them.

On another note efforts to create artificial islands and peninsula's might make sense for some nations due to rising ocean levels and a lack of areable land. Also technology to remove metals and fuels from sea-water could mature in the future. A water-world scenario in the far future doesn't seem to far fetched either. While a global flood is very unlikely it is plausible that we could have many industrialized entirely or partially inundated by rising ocean levels, thus necessitating greater marine development in the aforementioned areas.

Cordwainer said...

Useless wireless keyboard. Meant to type "not hard to do with" and "industrialized nations".

Geoffrey S H said...

I have feeling that in the case of rising sea levels Stephen Baxter's "Ark" would be more appropriate. Not the ridiculous sea-level rise in that book of course, but the general anarchy and total incapability of governments and peoples to deal with any significant sea rise does seem pretty on the money.

Eth said...

For a succesfull hard(ish) space opera, Alastar Reynolds did a quite good job.
Near-immortality and cryosleep gives sub-c interstellar travels at human scale. Interstellar ships are a rare supply that very few know how to build, so you don't see them turned into cheap WMD.
There are bits of technomagic, though, with the fuel-less drives being the biggest one (and possibly the less "hard"). You may replace it with mass/energy converters, like with "in the deepness of the sky". If you want to do hard-SF, have humans and have an interstellar setting, you can also seriously downgrade interstellar interactions, maybe to mostly signals to the neighbours.
It can still be a space opera if, say, the heroes are one of the very few interstellar crew ships, nomads travelling from world to world and seeing civilizations rise and fall.
It would be really hard to pull it off, IMHO, but not impossible.

Jollyreaper:
From Harry Potter. Imagine the implications of polyjuice potions in espionage. Or universal truth serums. Or the time-turner. You can muck with time?! And you're just using it to cram for tests or save a hippogriff? What about changing the outcome of battles! You have the makings of a proper Time War on your hands.
Indeed; I found Harry Potter incredibly frustrating as how the world makes no damn sense (and how even a teenager me would have tried to "game" some of the most ridiculous aspects of the world.
Polyjuice is but one of many examples. Their ultimate death spell can be deflected by a few cm of stone, they can invoke inert like chairs (or, say, bricks) seemingly at will. No-one thought about automatic weapons. Or automated, despite being able to animate pretty much anything. Their shields let light pass and they can produce light; laser blinders? Their economy is based on gold and silver money, while RL gold can fluctuate quite a bit. No-one thought about teleporting on the Moon? Or if it's out of range, no-one thought about magically launching rockets? That's freaking free energy we're talking about. Or maybe funnier stuff like causing magic-induced nuclear reactions, projecting supersonic bullets to unsuspecting targets before they can raise their shields, morphing air into chlorine or botulism toxin...
Though being unable to stop my brain with it (like for, say, Star Wars), I did finally found an explanation. MAGIC!
Or to expand, their magic, freely used and combined even with clever technology would be devastating. So at some point some people decide to create a world spell that will brainwash wizards and muggles to ignore each-other as much as possible. Hence how this insane dichotomy can continue without anyone trying to game it. Why muggles won't add 2 and 2 about something being really wrong, and why wizards show such an ignorance about muggles, and a strong repulsion to meddling with technology.
But wait, isn't there this guy who built a flying invisible half-sentient car in his backyard? Yep, the world spell is breaking. So it means that their version of PNF or PMF will its wonky tech will collide with the magical world with full force, at the surprise of both.
Now that would be a sequel that I would read...
("HP and the methods of rationality" can be quite fun, but be warned. If you disagree with some of the author's pet ideas or science points, it can be really infuriating.)

Still, if you want a good, believable urban fantasy with a magical secret world, there is the Dresden Files series as far as I've read.
Here, wizards & cie don't want normal people to know they exist because, even with magical power and stuff, they don't want to take the risk of a witch hunt, being a few hundreds against 6 billion people with ICBM and stuff. And even when things spill out a bit, normal people tend to forget or brush it off, as it challenge the way they see the world, where things can be rationally explained.

Cordwainer said...

Gold from seawater could be cheap and is resistant to sea-water but I think Jules Verne already built an underwater city out of that. Could be as simple as developing a long lasting corrosion resistant coating for metal, maybe if chemical vapor deposition technology matures. Seems more near term that advanced robotics or massive 3D printing, and would have plenty of other uses other than building floating islands.

Also depletion of certain metals and other resources along with an increased demand for certain resources could spawn an need for more marine resource utilization, which might spawn a need for floating "workshops" to conduct mining efforts.

Cordwainer said...

While sea rise might create anarchy for some I think the more powerful nations would have time to deal with the situation in constructive way. Other nations might not be so luck, but for them you would always have foreign government and powerful private special interests coming in to "help" deal with the chaos to their own benefit. Could make for an interesting reshuffle of current world politics.

Brett said...

It depends on the country. Countries like Bangladesh would be mostly screwed by major sea level rise as far as we can tell, but rich countries can take the Netherlands strategy and build dikes/dams/landfill/artificial reefs/barriers to hold off the sea while migrating in-land. It's expensive, but you're amortizing it over decades.

In Flood, the speed of the rise was the main problem. It was just happening too fast and too much for them to seriously adapt, and then they found out that it wasn't going to stop - there was no level of infrastructure they could build that would permanently keep back the sea from drowning human habitation on the land.

Ark was interesting, although I think they should have given that Uranus-tilt habitable planet a shot. Even if the equator is the only place that doesn't get some big seasonal shifts, you still should be able to find sheltered coastal areas that don't experience more than a few weeks in darkness or perma-day a year.

Cordwainer said...

I'm still holding out hope that some combination of incremental improvements in technology might make commercial space a little more interesting and sustainable.

Perhaps if you combined Evolved Delta with winged boosters or developing Star Booster type blended wing stages could be used as a fully recoverable OTV/Space Shuttle launch platform. Use Spaceship II/III type technology to launch pico-sats. Then have your Heavy Falcon launch fuel depots to further the range of your OTV's and Space Shuttles. The OTV's would dock with and remained docked with the fuel depots when not in use and would mainly be used for satellite de-orbits, major altitude corrections of satellites and clearing of space debris. Unmanned Shuttles would be used to refuel the depots and recover expensive satellites that fail early for repair or recycling on ground, they could also refuel from the depot and then be used to launch payloads into higher orbit. Manned shuttles could used for minor repairs and upgrades to satellites.

Automation, re-usability, recycling, and lowered cost of some of the launch methods could lower some of the increased costs of extra launches and development of new payloads. Problem is it would probably wouldn't defray all the costs and would require a great deal of initial investment.

The public and private sector would have to be sold on the "sustainability" and "increased flexibility and capability" pitch to properly fund such an infrastructure.

Jim Baerg said...

Damien: "esp. if someone developed something that was cheap and resistant to seawater corrosion."

One of the nice properties of titanium is its resistance to seawater corrosion, the ores are fairly common, but it's expensive to refine. However, there is research going on for something that would do for titanium what the Hall-Heroult process did for aluminum.


BTW Brett, I would be interested in your response to this:
http://www.rocketpunk-manifesto.com/2012/03/sailing-distant-seas.html?showComment=1343352512957#c7556834241715984610

Cordwainer said...

There are also investigating processes to make the production of aluminum even cheaper. If aluminum bronze alloys were relatively cheap to produce they might provide sufficient resistance to both fatigue and corrosion for a lot of applications. Of course if worries over peak copper pan out then that might put the kibosh on that idea. Of course utilization of undersea sources of copper along with other sources and better refinement/recycling methods could meet world demand indefinitely.

Brett said...

@Jim Baerg

Fascinating. I think it would be awesome to have a setting where you have a bunch of seaplanes traveling around.

Damien Sullivan said...

Copper is over $7/kg. Al is $1.80/kg. Ti is $6/kg. Scrap iron is I dunno, 40 cents/kg? Carbon steel is 80 cents/kg. Stainless steel (not actually resistant to seawater) is $3-5/kg? Concrete, maybe 8 cents/kg in bulk? Nickel's used for alloys, like 70-30 copper-nickel pipes, and is $13/kg.

Most of those corrode in seawater, I'm just giving prices for comparative construction costs. "Let's build using something 100x more expensive than concrete."


One source says if you want really seawater proof metal you want S32750 stainless steel, for which I see a cool $25-30/kg. Well, for coils; another entry was only $3.50/kg. Another says $5-12/kg. S31803 might suffice if your seawater isn't boiling; alibaba says $1-5/kg. I dunno, I'm way past my experience zone, though Wikipedia says duplex steels like that stay cost-effective because reasons.

Cordwainer said...

Going over Evolved Delta and current ideas for OTV designs for the space station and how to fit them into a more modular family of fully or mostly reusable vehicles. Here is what I was thinking.

1. An unmanned Blended Wing Body design with a flying boat fuselage for water landings and a payload bay with mechanical arm for launching and recovering small payloads. In space refueling capability.

2. A reusable manned capsule with finned surfaces, ballutes, drag chutes and rocket engines for controlled landings on water or land. Automated docking and flight in space. Small bays for storing personal orbital maneuver vehicles or rocket powered skiffs for astronauts to conduct repairs and upgrades on orbital vehicles. No pressurized bay astronauts ride up and down in space suits.

3. An unmanned version of number two. Astronaut bay is replaced with cargo hold and orbital maneuver vehicle bays are replaced with fuel tanks for fuel transfer missions to ISS and orbital fuel depots.

4. A large dockable stage with fuel depot/tug capabilities.

5. Large single universal type modular satellite. Common design consisting of a docking platform for docking and fueling with depot, fuel tanks and a skeletal frame for placing different modules. New or different equipment or propulsion modules can be placed on frame for specific missions.

6. Modular medium to heavy lift launch vehicle that can fit two to three stages. Utilizes different stages for different payloads. 1st and 2nd stages our of similar size and use a blended wing-body design for controlled descent and landing on water. 3rd and final stage used to mount vehicles 1 through 4 or fully equipped version of vehicle 5. 3rd stage uses Grasshopper style recovery system. 1st and second stages can be used to launch stripped down versions of vehicle 5.

7. Spaceship Two and Three with Pegasus style launcher for launching small payloads that would be inefficient to launch with number 6 launch family of rockets.

Yeah, I know nobody would willingly invest in such a concept it would be to expensive and inefficient. Cool idea nonetheless.

Unknown said...

Still a lot of abstractions here, but the actual BUSINESS case is what's needed.

Commercial spaceflight CAN be made into a solid business case, and in fact HAS been since the 1970s. Communications satellites and remote sensing spacecraft are both operated by private companies at a considerable profit. Government launch services make it possible; SpaceX and private launch services might soon make it cheaper.

Communications satellites, however, did not and will not lead to an expanded human presence because those satellites do not require a human presence to function efficiently. Asteroid mining missions will have this feature as well for quite some time, but unlike comsats there's a greater potential there for an eventual human presence to add value to those operations.

Cordwainer said...

On the subject of floating islands if you have enough surface area and buoyancy anything will float. Concrete might be alright if you have a way to keep it from getting wet. Weld steel bulkheads and rebar to your concrete for sufficient structural strength and to keep the seawater from eroding the concrete. Cover the top surface with a rubberized coating. Cover the bottom surface and surrounding "coastline" with air or gasoline filled bladders.

Cordwainer said...

I was merely looking at a semi-plausible scenario for a near term setting in space with limited human presence not the longer term projection of possible "mining colonies" in space. Of course such advances as I mentioned could benefit space tourism and possible lunar missions as well. An automated Space Shuttle-esque recovery vehicle might make lunar and martian sample recovery safer. Fuel depoting and heavy lift could make it easier to send and maintain and army of automatons on the Moon.

Eth said...

About concrete, I've read somewhere recently that they finally understood how Romans made concrete that is still in good shape despite being underwater for quite many centuries, while today's concrete won't last more than 150 years. It involves volcanic cinder and its Al ions, IIRC. And cheaper concrete, as you don't have to heat it as much.
So concrete may be a good material for long-lasting underwater constructions, and may be even better in the future as R&D on it isn't going to slow down.
Though it won't help for space. Unless someone builds a rocket whose first stage using Archimedes' principle? (Come on, that would be awesome!)

Cordwainer said...

Yeah, I visited Italy a long time ago and was always amazed at the Roman concrete works there. Some of them look brand new except for a few cracks. Even the stuff done during the Renaissance looks in better shape than the Hotels I stayed at, of course they've restored those over the years. But still it's surprising they have remained largely intact with very little in the way of structural damage for centuries at a time.
If we could even make concrete as good as they did in Michaelangelo's we would have better concrete than we do now.

Thucydides said...

One of the key reasons ancient concrete lasts so long is there is no metal embedded in it.

Concrete with Rebar is far stronger, but the rebar eventually corrodes and damages the concrete from within, making it more vulnerable to other damage.

If the rebar could be replaced by strong, non corroding materials (glass fiber, non metallic "basalt fiber", Kevlar etc.) then it could last for centuries rather than decades. The only downside would be cost.

Cordwainer said...

Covering the outer surface of the concrete with corrosive resistant steel might be just as cheap though. That's what they do for bridge pylons, metal containers filled with concrete. Good enough for a floating mining platform/temporary settlement.

Cordwainer said...

Their is actually an article on an engineering study in the advanced concepts forum of nasaspaceflight.com about hydraulic pipe launchers for use as pipe launchers. Such a concept would probably be expensive to build and design but it doesn't seem any less feasible then a Lofstrom Loop or Super Cannon. Like a super cannon your projectile/payload carrier would have to withstand enormous pressures, but due to waters higher density you could probably lift larger payloads. Don't know how comfortable the ride would be for any astronauts but I suppose it would be less dangerous than Leik Myrabo not positioning a mirror just right.

Cordwainer said...

typo: "for use as pipe launchers" meant to say "for use as space launchers". I ended up repeating myself. Shouldn't eat and type at the same time.

Cordwainer said...

I suppose if a hydraulic pipe launcher could launch a significantly large SRB then you could get rid or vehicles 6 and 7 from my previous post. If not then they might at least be used for quick high altitude/suborbital flight.

Anonymous said...

Cordwainer,
A few years ago, there was an experiment to create artifical islands out of calcium carbonate by emersing electrified wire frames in seawater. I haven't seen anything about how the experiment turned out, but since the news isn't blairing about a new island, I'd say it didn't result in the outcome they had hoped for, but maybe it gave them an idea for another approach.

Ferrell

Noclevername said...

"Kyle Allen said...
Still a lot of abstractions here, but the actual BUSINESS case is what's needed."

If we knew enough about the necessary finances to state a viable business case, we'd start a business, instead of just commenting on blogs about it.


Thucydides said...

Cord, can you post a link to this "Hydraulic Pipe Launcher?

Thanks

Eth said...

One of the key reasons ancient concrete lasts so long is there is no metal embedded in it.

Not only that, but chemical bonds in concrete are not as stable as they could be, and concrete itself starts to crumble after decades, even without metal bars rusting inside.
Today, concrete is estimated to last 150 years before starting to crumble. And concrete from 50 years ago is estimated to have 50 years of life, meaning that many buildings are now at the end of their life. As well as quite a few bridges and dams, I've heard. (How the hell do you replace a dam, btw?)
The particularly of Roman concrete is apparently the presence of those Al ions, in a way that result in far more stable chemical bonds, so can survive millennia without crumbling even undersea.
That's impressive when you think about it, that we have to learn from Romans about one of our main modern building materials.

Cord, can you post a link to this "Hydraulic Pipe Launcher?

Seconded, I'm very curious about the characteristics of such a launcher. What would be its performances and what would be the main challenges for creating one?

Thucydides said...

Lyek Mirabo should be pleased with this news from Poland.

For fans of the Laserstar weapons platform (or just high energy lasers in general), this is also good news, a compact amplifier that allows for very high power laser beams to be generated at high repetitions:

http://ichf.edu.pl/press/2013/10/IChF131003a_EN.pdf

The art of amplification: a desktop-size 10 terawatt laser

A compact new generation optical amplifier has been constructed by physicists from the Laser Centre of the Institute of Physical Chemistry of the Polish Academy of Sciences and the Faculty of Physics of the Warsaw University. The apparatus is
extremely efficient and small enough to fit on a desktop and is able to generate over 10 terawatt light pulses.

Anonymous said...


"The art of amplification: a desktop-size 10 terawatt laser"

Well, this should go a long way toward developng ler triggered fusion.

Ferrell

Anonymous said...

Damn wireless keyboard! that should be "...Laser triggered fusion."

Ferrell

Tony said...

Re: hydraulic pipe launcher

To get even a fraction of escape velocity you'd need pressures and injection rates that are beyond the capabilities of real world materials.

Re: Parametric laser amplification

Not weaponizable that I can see. Not even high enough energy to promote inertial confinement fusion. Yes, they're getting very high energy densities, but only for extremely short durations. They're talking about maximum theoretical efficiency of 50%? that means half of the energy is absorbed by something in the machine. So you still have cooling problems on the close order of your output energy.

Eth said...

This laser has what, a few joules? How much energy would it need at such durations to do interesting stuff (as fusion, weapons...)?

Tony:
To get even a fraction of escape velocity you'd need pressures and injection rates that are beyond the capabilities of real world materials.
What kind of performances could it have, and for what characteristics? What kind of (real, lab-only or speculative) materials would be needed? Even if it can't launch at Mach 1, a few hundreds of m/s, or eve a few dozen, may still help a massive rocket for liftoff.
For it to be more interesting than simply More Boosters is another question, though.
Also, would it need to be vertical?

Just asking around about what is actually possible, improbable, cost-efficient or simply impossible.

Thucydides said...

The way I am understanding the article is the amplification is much more efficient than previous methods (yes 50% is rejected as wast heat, but this is far better than the sapphire amplifiers used to date), and can be used at a high repetition rate.

Since it is relatively small, an amplifier stage based on this principle could probably be placed near the end of the optical train, maybe just before the beam expander and focusing mirror or diffraction grating. At any rate, it will be much simpler to place the amplifier and its smaller cooling unit than a comparable Sapphire amplifier.

As for ICF fusion, having the driving lasers delivering much higher levels of energy much faster can only be a good thing. As I understand it, the key deficiency of ICF is the fusion reaction starts and propagates much faster than the fuel pellet can be "crushed", so much of the fusion energy is simply used to blow the fuel away before it can fully "burn". A faster and more powerful "shot" could provide enough pressure to keep the fuel confined while the reaction takes place.

Cordwainer said...

I suppose multiple lasers might be used to create a counter-pulse to control the "blow-off" in ICF designs. I'm really skeptical that any laser-based fusion ignition system would ever be efficient enough to produce better than break-even performance. Although, imploding liner based fusion might make for an effective pulsed fusion space propulsion or energy generation system.

On the subject of floating islands I was reminded of Project Habakkuk by a poster displayed on a U-Haul today. Pykrete might be an effective means of building oil rigs and other structures in Arctic waters, of course you would have to find a way protect it from melting during hot summer months.

Question does anyone have any suggestions for advanced propulsion concepts for travel both on the surface and under the surface of the water. I was trying to imagine what a more advance marine based society might look like.

Geoffrey S H said...

Coming to an earlier point of discussion, I think its time we set 2 classifications on what we are discussing. We mostly seem to be agreed it will take until after the plausible mid-future to maybe around 700 years to get the rocketpunk future we all want to talk about (if it happens at all) and that a bunch of factors are linked with preventing it from happening, not just engineering principles and but also economic factors and the need for even more energy to study various breakthroughs and a wealthier population to boot. We do nevertheless want to discuss this kind of future as it is infinitely more accurate than the rubbish they put out on tv now- that's what got some of us discussing it in the first place.

On the flip side, if we want true accuracy, we aren't going to get any space future at all, certainly not in our lifetimes.

Thus I proposer we come to an agreement, and state what kind of future we are discussing first to avoid someone having to come in that say "you can't do that" to something that might be reasonable in a wealthier society but is definitely not so now. Maybe an outlining document (manifesto? ;) ) might be useful, the sort of thing that Atomic Rockets has at the start, but even harder (!) sf.
Therefore- we perhaps should state before each point whether we are discussing near future ideas for satellites, "low" ambition drone missions, or far future concepts that are accurate but nevertheless take into account such a pass of time, and factor in new materials, wealth levels and technologies (but perhaps not specifying exactly what they might be so we don't have the whole "how do we get fusion to justify torch-craft" problem. State the capabilities of such things and work out how they would affect the world around us, and mix them together, but don't state too specifically what they are).

On a side note, building a rocket-future in the latter half of this millennium can be quite fun. I did it with a 90,000+ word world building exercise I've been doing, and it worked quite well. You jjust have to do 500 years of world building before hand, which is quite interesting to do as of itself.

Geoffrey S H said...

Urgh, apologies for the long sentences, has been a long week.

jollyreaper said...

I have not caught up with the posts but have to say Gravity is good stuff.

To be fair, it's got a lot of technical flaws and fudges. The orbital mechanics are just not right. The Hubble and ISS and Mir were never in the same orbital plane and visual range. There's no Chinese station. But this is nerd wrong. The things they get right are stuff that will impress the general public.

No sound in space. Period. Only the sounds you would hear from inside the suit and with physically holding structures, or being inside a pressurized area.

Everything is zero g.

Very long takes with a solid appreciation for the gorgeousness of the environment.

Good acting and watching people try to keep it together in high stress situations.

Neil Degrasse Tyson was tweeting about all the scientific problems with the film and he wasn't wrong but he was missing the point.

It's good stuff. See in 3d.

Anonymous said...

Geoffrey wrote:

"Thus I proposer we come to an agreement, and state what kind of future we are discussing first to avoid someone having to come in that say "you can't do that" to something that might be reasonable in a wealthier society but is definitely not so now."

That sounds like fun.

For this near future sci-fi exercise, let's stick with the flight rate issue Rick brought up. Let's assume that someone has solved the flight rate issue by developing an inexpensive reusable launch infrastructure that dramatically reduces the cost to get to orbit. Now that you have solved the "halfway to anywhere" problem, what could you do?

You still have operations costs, travel time issues, what's the economic justification, etc. Any ideas?

One that jumps to mind is that LEO space tourism becomes practical. Anything else?

Ron

Anonymous said...

How about a habatat research station on the moon, or solar power research stations at L4 and L5? Those should be specific enough and 'doable' enough to increase launch rates a bit.

Ferrell

Cordwainer said...

Well, if you had relatively cheap advanced robotics and 3d-style printing machines for producing your space infrastructure that in itself would lower your launch and operations costs. Combine that with some type of permanent reusable launch structure like a rotovator, space elevator, launch loop, pipe launcher etc. and you might have something that gets you half way there. Initial investment would be high, but if you have the aforementioned advances in production then it might not be prohibitively so. Such reductions would be in enough of a grey area that you could get away with it from a hard sf angle, I think.

If you have the "halfway there" problem solved then it actually makes sense to build more modular infrastructure in space. Modular satellites, inflatable space habitats, repair tugs, orbital parts bins all become doable. Even some in-situ use of resources on the Moon to build that infrastructure becomes plausible.

If your solution to the energy crisis happens to be some sort of high efficiency photo-phoresic or microwave rectennae technology like Heinleins's sun-screens then orbital beamed power stations become a more useful and possible development.

One idea I had for a story is a future where we find deep caverns on the Moon built by some ancient and now long gone alien civilization. Humans turn the caverns into a colony and discover alien technology. Hard SF take on such discoveries, mostly they just learn to replicate alien structural materials. By accident they discover a materials based beamed power technology that uses meta-materials to produce high transmit and absorption efficiencies or allows for some type of gravito-magnetic interaction or field separation effect. Now you have a setting with beamed energy and possible reactionless propulsion systems.

Tony said...

I feel constrained to interject a reminder that LEO isn't halfway to anything if money is an object (and it is). As previously pointed out, even our presumably primitive launch vehicle technology makes getting into orbit a minority of the life cycle cost of any space project.

Now, some will try to reason that the more people operate in space, the cheaper it will get. There's some truth to that, but there is also the "you can't get there from here" problem of it costing so much to begin with that volume traffic will never develop. And I'm not so sure that society is likely to get all that much richer in terms of productivity at the levels of durability and reliability that space requires. It's not just a matter of applying cheaper energy and more automation, like making lawnmowers.

Geoffrey S H said...

@Tony:

Agreed, it is highly unlikely that people will just "get richer", even over a long span of a few centuries. It does however seem the most mundane (and thus least likely to have more plot holes in it than Swiss cheese) way of getting spaceflight in a long-term "plausible" setting, as opposed to silly flashy magitech and badly thought out cost saving measures that just don't work. Personally I'd rather bring the cost of everything "down" in one fell swoop and have someone go "that's unlikely", than try and fiddle with untried/unworkable space tech, shave a few tons off the equipment through questionable assumptions, improve the cost efficiency of a whole range of products and toss majitech into the bargain and have it become an entire mess of "that unlikely"s.

Cordwainer said...

I did say the initial investment would most likely be high, Tony. As you pointed out that even with better power generation and manufacturing technologies one would still have to design and build machines to be durable and reliable enough for operation in space. Also, you would have to a profit-incentive reason to expand your space infrastructure beyond just satellites.

Perhaps, heavy reliance on fusionables and rare metals might necessitate greater use of marine resources. Developing the technology to exploit those resources might create the need for some of the durability and reliability you would need for a space program while also creating a greater incentive to exploit our moon for those same resources. Yes, I know it's not the same thing but operations in the vastness and vacuum of space do have some things in common with underwater operations. Structural durability of components and the need for high density energy storage for power supplies to name a couple.

Of course short of a global catastrophe or an alien invasion I still don't see the need for developing a large human presence in space for centuries to come.

Cordwainer said...

Also, I'm not exactly sure what Geoffrey means by society would not get richer over the span of centuries. Globally humans have gotten richer over just a few decades, and the technologies and changes that fueled those increases in wealth were not exactly that revolutionary or sci-fi gimmicky when you look at them objectively. Combustion engines, electricity, improved sanitation, vaccinations,computers and the internet are hardly gimmicky or all that out there. People were experimenting with these ideas long before they became a reality.

It seems quite plausible that advances in robotics, manufacturing process and structural materials could bring about a scientific and technological renaissance. Very likely within a few generations, no. Within the realm of plausibility, yes.

Tony said...

To make a long story short, the Renaissance and Industrial Revolution already happened. Whatever would change the balance of resources and needs in favor of greatly expanded human space occupation would be something entirely else.

But the balance of the known vs the unknown -- at that fundamental level I keep talking about; the level where substantial changes in scientific paradigms and engineering practice are found -- is constantly changing towards much more known than is unknown. (Because there is a finite level of fundamental knowledge; we won't keep finding new physical principles tomorrow just because we found some yesterday.) Additionally, the amount of accessible new knowledge is reducing rapidly, simply because we can't generate and control the levels of energy required to keep probing.

So the plausibility of a greatly changed future just doesn't exist for me. As much as I enjoy it, I have to treat space opera and a space opera type of future as totally implausible.

Cordwainer said...

Sorry I was using "renaissance" in a loosely ambiguous way. While I'm not very optimistic that we could ever see substantial "Star Trek"-like changes in our future. I think it is reasonable to assume that we could see paradigm changing technologies in the near future in the areas of electronics, manufacturing, structural materials and nano-engineering that would change our lives significantly. Yes the Rennaisance, Industrial Revolution and Computer Age happened already that doesn't mean that another significant technological event couldn't happen in the near or far future. Even if we are fast approaching a wall in terms of physical laws as to how well we can further manipulate our environment, doesn't mean we don't still have room to progress technologically. I'm not talking warp drives and nanites. I'm just saying it's not beyond the pale that we might develop better automatons and better manufacturing and material processes that might enrich us in ways we can only guess at right now.

Tony said...

Cord,

The difficulty I see in your conjecture is that we've been working at the cutting edge of physics in everyday engineering for decades now. The transistor, for example, is an engineering implementation of quantum mechanics, and it was commercialized within ten years of the underlying physical theory being published. If we don't have new fundamental knowledge, there isn't going to be any engineering innovation based on fundamental knowledge. The lag times just aren't that long.

Cordwainer said...

Actually, Lilienfeld thought of the idea for transistors in the 1920's but the manufacturing methods needed to make transistors cheaply were not developed until the 40's, even then it took 10 years for engineers to develop and fully commercialize transistors for use. That is actually quite a bit of lag time compared to advances today.

Also, your argument has little to do with the modest improvements I'm talking about. It would not require a great leap in computing power, energy storage density or material processes to have sci-fi like advances in robotics and structural materials. There is still plenty of room when it comes to working with nano-engineered tolerances to produce some pretty cool meta-materials as well. Such advances are more likely to be stymied by economics than any arbitrary physical limits. The physical constraints are more likely to factor into the cost of production not whether such products can actually be manufactured. So while I agree that there will probably not be any one factor the expedites such developments, given time and ingenuity such developments could occur.

Anonymous said...

BTW, "halfway to anywhere" is the Heinlein quote that refers to delta V. That's the energy required, not the cost. Still cost is an issue. Even if you could get to LEO on the cheap, say by a space elevator or some other crazy tech, traveling anywhere else would expensive.

Economics still rears its ugly head. Space solar power beamed to Earth really will never make any sense. It will always be cheaper to just build it on the ground. Lunar and Martian bases or colonies would be cool, but other than a very small research base, why would you build them? There isn't anything they could make to trade that would be worth it. Asteroid mining would be useful to build space structures, but why are you building space structures? Where's the profit in that?

At least for the near future, the only reason to go would be for exploration. That's still a pretty good reason and I'd like to see it.

Ron

Tony said...

Ron:

"BTW, 'halfway to anywhere' is the Heinlein quote that refers to delta V. That's the energy required, not the cost."

I think all of us are quite aware of that. What many aren't seemingly aware of is that delta-v is a marginal cost factor, even when most of the physical launch vehicle is used up to get "halfway". The cost of space systems is the real killer.

Also, as a technical aside, LEO is only halfway in delta-v terms if you're going no further than Mars and you're using minimum energy orbits. If you're going past Mars and/or you're using higher speed transfers, not so much.

"At least for the near future, the only reason to go would be for exploration. That's still a pretty good reason and I'd like to see it."

It's a highly valid reason, if you see man as more than a producing and consuming economic animal. But one still has to balance the cost against the available resources. (Not just the physically available ones, but -- perhaps more importantly -- the socially available ones.) In that realm, human spaceflight is likely to be a very exclusive endeavor for a very long time.

Cordwainer said...

All, good points. Beamed power to Earth's surface would never be cheap enough to justify it's creation. Although beamed energy in space for beamed propulsion, providing power to habitats or screening debris from orbit might be justifiable. I would argue that lunar and asteroid mining of resources might be of value here on Earth, but only in the far future when resources are far more depleted or are far more needed due to increased societal demand. Of course there is also the argument that in-situ resource utilization might be useful for future exploration and space tourism purposes as well. Getting to that "halfway point" does make it far easier from an economic point to make use of such in-situ resource utilization, and cheaper more advanced automation and manufacturing could make it even worth it from an economic point of view. Exploring the Moon or Mars with self-replicating machines for instance. Of course you would have to have a reason to develop self-replication in the first place and then adapt it to the environment of space.(highly unlikely)

Cordwainer said...

As, Tony has reminded us it is really the cost of space systems that is the killer. Hence the reason I keep beating the dead horse of improvements in manufacturing and developing more modular or more independent(in-situ utilization, self-repair/self-replication) space systems. It's not a perfect solution but it is probably the only one that would have a reasonable chance of working in a pseudo-hard SF setting. Of course with the development of such technology and the enrichment of society that such technology would create, you would still have to justify it's used in space either from an exploration or economic angle. Such technological changes would have to great enough change in wealth to justify space travel either for purely exploration reasons "because we can" or produce such a demand for certain resources that asteroid and lunar mining become attractive.

Damien Sullivan said...

"Globally humans have gotten richer over just a few decades, and the technologies and changes that fueled those increases in wealth were not exactly that revolutionary or sci-fi gimmicky when you look at them objectively"

A key element was using far more energy than we had before. Coal, oil, natural gas, and using those to do work via steam engines and electricity and IC engines.

For much of the world they're still looking to use more energy, but that's catchup with the First World, where the trends are more toward efficiency and replacement energy sources that won't screw the climate. Sustainability rather than energy growth.

And if you do the math then extended energy growth over centuries would look rather problematic.

Physically there's still lots of unknown -- dark matter, dark energy, i.e. most of the universe -- but it doesn't look very technologically promising at the moment.

AI probably doesn't need new physics and could revolutionize space *and everything else in society*. Singularity, not space opera.

Anonymous said...

Tony:

"I think all of us are quite aware of that. What many aren't seemingly aware of is that delta-v is a marginal cost factor, even when most of the physical launch vehicle is used up to get "halfway". The cost of space systems is the real killer."

Supporting manned space systems is expensive, but most of that cost is sending replacement crews and supplies to LEO. Cheap access to LEO would be a big help.

"Also, as a technical aside, LEO is only halfway in delta-v terms if you're going no further than Mars and you're using minimum energy orbits. If you're going past Mars and/or you're using higher speed transfers, not so much."

You are partially correct. Unless you have a torch drive, you are going to use minimum energy orbits. We're also talking about getting out about as far as Saturn, not Mars. The delta V from Earth to Mars is less than half of what it takes to get to LEO. Now if you are including landing on Mars, you are correct. You can go from Earth orbit to Jupiter orbit for less than what it takes to get to LEO. Depends on your mission.

Cord's discussion of advanced robotics is interesting and could provide more cost effective space exploration, but that is the sort of thing that makes manned spaceflight in the future less likely.

Ron

Anonymous said...

Those are all good points, both pro and con, but what practical methods would everyone suggesst for increasing launch rates in the near term? I think that creating and supporting off-world research outposts would be a good way to do that...what other ideas do you have?

Ferrell

Anonymous said...

I think an EML2 station would be good for Lunar and later interplanetary operations. That would get us going with BEO research.

In the near term, commercial operations can be used to supply government operations and maybe even a LEO space station to rent for research. That's what SpaceX, Orbital, and Bigelow are up to.

Business needs to make a profit, even nonprofits need cash flow. As Tony mentioned, space operations are expensive. I'm having a hard time seeing a business case for doing anything in space other than research and shipping for the government.

Of course, privatizing LEO access could be good enough for now. If a government needs to get to orbit, hire a LEO 'trucking' company.

Ron

CarlVon said...

Space Combat is finally here, this site inspired me :)

http://spacesimcentral.com/ssc/topic/3986-tspace-tactical-space-combat-fleet-simulation/

Geoffrey S H said...

Might asteroid mining be useful if most earth metals are used up in the long (long)term?

Jim Baerg said...

Geoffrey S H:

That depends on which metals.
Since iron aluminum & a few other metals are each several % of the crust, we can't run out of them as long as we have any sort of adequate energy supply.

However some metals are rare in the earths crust but relatively abundant in asteroids. See:
http://en.wikipedia.org/wiki/Goldschmidt_classification#Siderophile_elements

I've always rather liked those as one of the more plausible McGuffinites to make space travel pay.

BTW this article
http://theenergycollective.com/nnadir/229901/adventures-fission-products-would-transmuting-technetium-be-good-idea
has some interesting information on important uses for one of the rarest of these siderophile elements & a possible alternative.

Thucydides said...

Unless and until robotics takes a really big leap forward, there is at least one plausible reason to have humans in space: as teleoperators for devices where long lightspeed lags would make doing productive work (science or asteroid mining) too difficult or unproductive. The costs of having people would have to be less than the projected benefits of a working fleet of robots.

These would not be massive bases, but maybe a few radiation hardened modules for living and a control station module. Each worker would be overseeing several robots and available to step in if one gets into some sort of trouble. It might even be worth while to have a small checkout and repair bay, although "repairs" will be hot swapping faulty modules rather than wrench bending.

Even then you are looking at something like the ISS and maybe a 10 man crew to oversee a small fleet of robot workers or explorers, and conditions will be much like a modern automated mine or oil platform. Building will involve multiple launches, but each launch will put one "big" assembly in orbit to minimize overall launch costs and the costs of orbital assembly (dock 3 big modules to the truss rather than a dozen).

WRT the question upthread about advanced propulsion for aquatic use; look up "Supercavitation", particularly in torpedoes and possible use in small submarines.

Byron said...

Tony:
I think all of us are quite aware of that. What many aren't seemingly aware of is that delta-v is a marginal cost factor, even when most of the physical launch vehicle is used up to get "halfway". The cost of space systems is the real killer.
I wouldn't classify delta-V as a marginal cost factor. Delta-V turns into hardware, and adding more can be really expensive. In fact, I would go so far as to say that space systems cost as much as they do partially because of how expensive delta-V is. Cutting a few kilograms and fitting the spacecraft on a smaller rocket can be worth a lot of money.

Also, as a technical aside, LEO is only halfway in delta-v terms if you're going no further than Mars and you're using minimum energy orbits. If you're going past Mars and/or you're using higher speed transfers, not so much.
Yes, but delta-V isn't something delivered to hardworking rocket scientists in tanks and pumped into spacecraft by liquid volume. Once you're in orbit, you have a lot of options you don't when sitting on the ground. Electric propulsion. Low-thrust, high-exhaust velocity rockets. Various maneuvers to steal delta-V from nearby planets. "Halfway to anywhere" is fairly accurate in a poetic sense, if not a strictly physical one.

CarlVon:
Space Combat is finally here, this site inspired me :)

http://spacesimcentral.com/ssc/topic/3986-tspace-tactical-space-combat-fleet-simulation/

Wow. I actually tried to do something similar with Excel a few years ago, but I wasn't enough of a programmer to pull it off. I still have a lot of information, though, and I'd be happy to help.

Byron said...

Thucydides:
Unless and until robotics takes a really big leap forward, there is at least one plausible reason to have humans in space: as teleoperators for devices where long lightspeed lags would make doing productive work (science or asteroid mining) too difficult or unproductive. The costs of having people would have to be less than the projected benefits of a working fleet of robots.
Interestingly enough, I have a RAND study on humans in space on order with interlibrary loan. It might be a while before it gets here, though.

Byron said...

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