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The Business Case for Reusable Launch Vehicles
An anonymous reader writes "Remember the failures of "shuttle replacements" like VentureStar? A Space Review article argues that even if VentureStar succeeded technically, it and other proposed big RLVs would never have made it financially: they cost too much to develop and wouldn't have made it up through increased launches. What's the solution? The author says that suborbital RLVs, like what Carmack, Rutan, and the other X Prize contenders are working on, will create a business cycle that will eventually lead to orbital vehicles."
space isnt really a profit generating place, its the ultimate R&D centre for exploring new technology and seeing how far mankind can go, if you wnat to make a profit sell vegtables on a market stall
I must respectfully disagree. It's not profit-producing because up to this point, it's been handled by large, inefficient government agencies. Get suborbital cost down below $1 million per launch, and profit will flow.
What's the real value of going into space? This isn't a troll; I really want to know. Why spend the money?
The problem with incremental development of RLVs is that there's a huge
leap between the size and difficulty of putting something into space
for five minutes (as in the current X-prize contenders) and putting it
into orbit (as in the shuttle). That will make it difficult to evolve our
way into a commercial space program.
I often find myself pointing out that just getting into space isn't
all that hard. Lifting yourself up 100km requires about a megajoule
(that's the energy equivalent of a stick of dynamite, or about 1/12th
of a gallon of gasoline (about 1/4 kg or 1/2 pound of gasoline), or a
jelly doughnut, or running a hairdryer for 2 minutes) per kilogram of
mass.
By contrast, orbital speed is something like 7000 meters per second,
(or 16,000 miles per hour for you provincials). Getting going that fast
requires an additional 24 megajoules per kilogram of mass (for a total of
25).
In short, the difference between the amount of energy you need to
get into orbit and just into space is a factor of 25, for the same
mass. That ratio of 25 is about equal to the difference between the
latent chemical energies of broccoli and gasoline.
Except that, in the case of space travel, you better be burning
something at least as energetic as gasoline to start with, or you'll
never even hoist yourself up 100km.
The way we've traditionally gotten into orbit is to concentrate the
kinetic energy into ever smaller bits of the vehicle: you use a huge
rocket motor and tanks to get everything started moving, then ditch the
empty tankage and rocket motors for the first stage -- that lets you
concentrate on moving a smaller amount of stuff even faster.
Realistic reusable designs are usually not staged designs,
because it's hard to recover and reuse the first stages. The problem is
that you have to have incredibly lightweight tankage and engines to make
everything work. But pushing stuff to lighter weight makes it more
flimsy and less prone to being reusable. Darn.
The VentureStar, IIRC, ran into problems with exactly this technology --
they were using lightweight carbon fiber tanks to hold their propellant,
and they couldn't make the tank light enough to boost itself into orbit.
The shuttle is NOT a reusable vehicle in any but the most technical
sense of the word: it requires constant skilled redesign and intelligent
(rather than scripted) maintenance, and the engines have to be overhauled
after every flight.
Heh, before I so hastily tapped the "return" key, I meant to add: Private agencies don't spend $100,000 on a toilet seat, and freed from that web of costs incurred from beaurocracy (sp? crap!), the industry can flourish.
We already developed the Eagle RLVs for Moonbase Alpha more over 4 years ago. Ask Commander Koenig.
The types of subsidy commercial entities are able to offer to space travel are nothing to scoff at, either. I would be willing to put up with advertising on the side of a shuttle, or under an orbital satellite, or even time-limited advertisements on the moon if it meant people got to ride there for free, and people who would complain about such things are no better than the ones who won't explore the heavens and won't let anybody else do so, either.
We've got to start looking at these alternatives if we're ever going to get anywhere.
Has any thought been given to reusing the main rockets? A friend once suggested getting them into orbit and using the shell as add-on modules for a space station. It seems like it would save time and money.
All that is necessary for the triumph of good is that evil men do nothing.
Having the capability for non-Earth-based scientific research and living is something that is sorely needed these days. Humans are taking over more and more of the non-ocean surface of our planet, reducing the botanic resources available. What could this potentially mean? That we could ultimately require so much space that we can no longer grow those items that are required for our species to live on: plants that generate oxygen for us to breathe, as well as the sustenance our bodies need to survive.
Granted, this worse-case scenario would be a long time off, but should we achieve the ability for orbital/sub-orbital vehicles, we will also have the potential for non-Earth-based research laboratories and research centers. There are many scientific endeavors which cannot properly be studies in a gravity-based environment, and by having research stations in orbit, we can test new botanic possibilities as well as other scientific experiments in orbit, while we humans live on below.
Given that God is infinite, and the Universe is also infinite, would you like some toast?
that sounds really cool! i can't wait for that next quake version =)
uhm, what do you mean that carmack... oh nevermind
From the article: A study conducted by the Aerospace Corporation for the US Department of Commerce last year identified a number of promising markets for suborbital RLVs in addition to space tourism, including remote sensing, microgravity testing, and missile defense applications. All of these are either unserved or underserved by existing sounding rockets. Does the military fund any sort of projects of this kind at the moment? If not, it would make sense to try getting money through them, since it seems easier to get funding for (defensive) military purposes than space vehicles.
The best picture I could find was this one on HowStuffWorks.
Comment forecast: Bits of genius surrounded by a sea of mediocrity.
The one and only point of RLVs is to be cheaper than one-time use vehicles. But they aren't. The technology and the engineering just isn't there to make them so. As an idea, the RLV has been proved to be completely worthless.
Now, it is possible through economies of scale to bring costs down a great deal. Look at what the Germans managed with the V2 rockets. But we aren't bombing England here, and there is no reason to make that expenditure right now -- certainly not for a million dollar "X-prize." And there is still no guarantee that RLVs will surpass the cost savings of one-time use vehicles.
It's imagination. The aviation industry used to have a handful of folks who could imagine and conceptualize the darndest vehicles - and a slew of brilliant engineers to turn those concepts into reality (or dis-prove the concept based on technical limitations, materiaks, etc.)
Nowadays, money issues and the eternal pursuit of higher profit margins has forced many of the dreamers out of the big aerospace companies and into places where there simply isn't the technical base to turn their ideas into anything at all. That's where the X-Prize will hopefully bear fruit - IF (when) the prize is claimed.
How long did it take for Trans-Atlantic airlines to start showing profits after Lindy made his flight? It's a rhetorical question, but the answer might be interesting, nonetheless.
This sig is a test. If this had been an actual sig, you would be reading something quite a bit wittier than this now.
sigh. yeah, i meant doom
From my point of view, you seem to have hit the nail on the head. RLVs are something that our current energy sources just can't dream to achive. We could build the vehicle that could sustain it, but we currently have no way of powering that vehicle.
IIRC, this is the reason behind the space elevator. Thus, we can get into space and dock with something already in orbit. Then we can transfer to some other station where work on space only vehicles can take place. These vehicles can then take advantage of ION Propulsion since it provides a constant acceleration.
My degree isn't in aerospace engineering, neither i have i even attempted to read futher on either of the above concepts other than a quick glimpse, but it seems to me that we are going about things in the wrong direction. I wonder what it will take to bring that revelation that suddenly changes everything?
Don't waste time... procrastinate now!
I didn't read the article, because I've seen too many like it already. It is motivated by capitalist dogma. The fact is that space exploration does not make business sense. There is nothing stopping businesses from building these things right now, if the "market" could support it. The technology exists. The only way to support construction of these things right now is by government support, and the justification is not "it makes business sense", but because the knowledge gained through them is of benefit to humanity.
What do they honestly recommend? That we wait while individuals businesses develop inferior, and largely useless, suborbital vehicles in order to "create a business cycle", when the technology to build more useful orbital vehicles exists and has for decades? It does't make economic sense, and it certainly doesn't make sense if you believe space travel is in the greater interest of humanity. Like the internet, there may be a day when space vehicles are cheap enough that building them and operating them DOES make business sense, but like the internet, it will get there through public investment, not the dogma of economic liberalism.
There is no incremental path to ski-jumping, either, but somehow people do it.
What we require is engines with a large thrust to weight ratio. When the airplane was being developed, this was a problem, until the gasoline engine came along. We also require strong, and lightweight materials, and design (see the airplane). Fuels that have a large energy content in relation to their weight (antimatter). And of course there's always the economic angle (cheaper is better).
Thus proving that nobody RTFA, nobody has erstwhile mentioned the "Delta Clitter".
People now pay $5000 to fly a MiG for a few minutes; imagine how much they'll pay to gaze out the window at a big blue marble!
"Freedom means freedom for everybody" -- Dick Cheney
While the article does make some good points about the high development costs, technological hurdles, and poor ROI on reusable orbital vehicles, I think that there is very little evidence of any solid business case for reusable sub-orbital vehicles. Just because it's not cost-effective to build and fly ROVs doesn't somehow make RSVs any more logical.
As a development step leading to the next ROV, an RSV may make sense. I am the first to admit that *anything* that gets the public to refocus their attention (and money) on the pursuit of space-related technological goals is a good thing, as it will inevitably drive the aerospace industry to push the engineering envelope in many areas, particularly in materials science (things like new composites, high-temperature ceramics, etc.). Technological advancement is a worthy (and, ultimately, profitable) pursuit.
But, in and of itself, as a "working vehicle", I can't see any suborbital spacecraft making money. There just aren't that many rich "space tourists" around to subsidize this as an industry. Suborbital vehicles are completely useless for the two main "space jobs" that countries and/or companies are willing to pay for: satellite launches and trips to the ISS.
Low Earth Orbit (LEO) is a useful destination. If you can get "stuff" into LEO, later trips can bring more "stuff", and, if you bring enough pieces of another space ship to LEO, you can assemble them there, and can go to other places. In terms of energy, LEO is truly "halfway to anywhere". One of the (rejected for complexity and deadline reasons) proposed Apollo moon landing plans involved assembling a Earth-to-Moon ship in LEO from modules launched over a period of time using multiple smaller launchers.
But, suborbital vehicles, by definition, can't reach LEO. Anything launched sub-orbitally *will* return to Earth, usually sooner, rather than later. There's simply no market for delivery vehicles that always bring their cargo back, and never leave it at the destination!
Bottom line: it may make sense to use an RSV as a technology test-bed as a step on the path to developing an ROV. It makes no sense to develop an RSV as an end in itself.
Well, the article makes a case for how the X-prize entries could be the springboard to cheaper access to orbital space. It seems like a nice idea, but it remains to be seen if that's the direction it will go in. I'm sure the X-prize backers have in mind a scenario like that for expanding the scope of non-governmental space efforts.
As for an RLV, it is true that only one design has ever flown; however, to give up on a whole class of vehicles when we're still on the 1st model seems very premature. Here's one remarkable fact about the Space Shuttle Columbia: their was a breach in the wing and the it was coming apart. Yet the craft (and its software) was actually able to maintain level flight until the wing actually broke off.
Are there flaws in the shuttle? You bet. But with 125 flights under their belt, NASA has a much better idea now how to build a reliable RLV. We're a long way from an operational vehicle, but that's only because of the high cost (and subsequent low number) of tests and launches. Maybe the X-prize entrants will solve this problem, or maybe a 2nd generation RLV will make a quantum leap in improvement-- today's big, dumb boosters are a lot better than how they started out; I bet the biggest improvments were early on.
So good luck to Armadillo and Scaled and NASA. If congress allocates the funds for NASA, I'm sure they can build a better, safer shuttle. If not, private industry will get there someday.
This wasn't a troll, and I doubt it was even read through and comprehended fully prior to modding it as such. At best it may be offtopic, but my idea was meant to spark conversation regarding this possibility. Mods, please learn to *read* before you click.
I'd be happy with some of that space broccoli.
A programmer is a machine for converting coffee into code.
Yet, RLVs continue to be the Holy Grail of the launch industry. Develop an RLV that can reduce the cost of space access to some magic number--sometimes $1000/pound, other times as low as $100/pound--and the world will beat a path to your door, industry pundits and advocates claim. Such a vehicle would open space to wide array of new markets currently shut out by high launch costs, from manufacturing semiconductors and protein crystals in microgravity to orbiting brothels for thousands of tourists.
Ed, one of the guys aboard the ISS currently, wrote his take on the future of spaceships, which i thought was a good read.
Don't forget that all this stuff called "air" gets in the way at times. Once you're 100 km above the surface of the earth, speeding up is just a matter of pushing yourself forward; starting from the surface, you need to worry about pushing all that air out of the way.
I don't know any sort of exact figures, but I'm sure the ratio is much less than 25:1 when you consider the energy lost to air resistance.
Tarsnap: Online backups for the truly paranoid
That big blue marble is my home you insensitive clod!
The unofficial
...then imagine how much they'll pay for the experience of zero-G sex! Screw the mile-high club, I wanna join the 800-mile high club!
On the contrary, that's how you learn -- you start by skiing downhill, then you jump over a low mogul, then you try higher and higher jumps until you're in the aerodynamic regime at terminal velocity. Then the size of the jump doesn't matter anymore, and you're ready to schuss down the Olympic ramps...
You're out a bit with that hair dryer. At 2400W (max in places like Australia and New Zealand), it takes 416 seconds to go through a MJ and 555s at 1800W (max for North America (I think: I might be wrong about the 15A)). That's not quite 7 minutes and over 9 minutes, respectively. Even then, I don't think I'd want a 1800W hair dryer pointed at me. That's no hair dryer, that's a hot-air paint stripper!!!
Bill - aka taniwha
--
Leave others their otherness. -- Aratak
Not really. Once you're above, oh, say, 40,000ft or so (IE, and minute or two after launch) you're above 99% of the air.
TODO: Something witty here...
Whup -- ya caught me! I slipped a decimal place (1kw vs. 10kw)...
Yeah... how can we link this stuff to sex, curing baldness, or creation of larger/harder erections?
;)
"Old Whitey" would cough up some major dough for that!
Diplomacy is the art of saying, "Nice doggie!" until you can find a rock.
"Don't forget that all this stuff called "air" gets in the way at times. "
Then strap a RLV to a weather balloon and release your vehicle at the apogee of the balloons flight. It's all "up" from there.
About what I thought.
Just as the Wright Brothers did not go from the Wright Flyer directly to a 747, or even a DC-3, we cannot expect to jump from expendable rockets immediately to large orbital RLVs.
Except suborbital rollercoasters are more like Oriville strapping Wilbur to a kite and tying it to the bumper of their pickup truck. There's no logical economic path from that to even a Wright Flyer.
or Blow if you prefer, but as long as we keep using them this whole space exploration going to consist of nothing more than hop around the moon at best and a few robot probes.
Time to start considering real concepts like Daedalus or Orion.
The markets which such RLVs will serve also seem to be dominated by government. Missile testing? Remove sensing? I can't remember having bought a missile or whatever the hell it is that a remote sensor gives you lately. Seems like we'll be paying for it through taxes for a long time yet.
Tourism. "To boldly go...". There are enough people out there that will pop $20k for a taste of space, considering how many pay to go to Antartica or Everest
Package Delivery. When it absolutely, positively has to be there in the next 2 hours.
As one of the X Prize contestants has already pointed out extreme skydiving.
And beyond that, how long did it take to go from the Wrights to Pan Am? And that was without the "help" of an oppressive government agency."Only two things are infinite, the universe and human stupidity, and I'm not sure about the former."
Hope you're a quick one, I think John Carmack's gets you about 3 minutes up there.
and don't forget, much like the rockets that came before it, most of what gets the shuttle into orbit (the external tank) gets dumped...in this case into the Indian Ocean...
I stole this sig from a more creative user.
Of course, the (disposable) booster stage would be much bigger and more costly than what they use now, but it still might be a win... emphasis on might. :-)
120 character sigs suck. Make it 250.
If you have read the CAIB report, one has to ask :
1) Why and how did Linda Ham go from being against additional imagery and questioning threat to orbiter issues to grilling the management team in three days?
2) Why did the management team go from demanding additional imagery at first to claiming "all the evidence" shows a safe, single return over the same three days?
3) What was Linda Hams' rationale for terminating all requests for additional imagery over a 90 minute period one morning?
4) Why did Rocha go from demanding additional imagery to insisting a safe return was probable?
5) Who in the USAF questioned what was happening at NASA when they noticed an imagery request come in, only to be cancelled 90 minutes later by Linda Ham?
6) Should the public demand the immediate resignation of all shuttle management who made the statement "Why do anything further? There is nothing we could do anyway", given that the CAIB outlines two specific scenarios that would like have saved the astronauts and Columbia?
The earth is a penal colony for the stupid, the lazy, the criminal, and the insane. (I fall into all of the above...)
In short, unless you plan on not coming back, don't bother trying to escape.
---
Earth has no survivors. Everyone who has ever been born here, has died here.
Someone probably assumed you were smart enough to know how expensive it is to send stuff into space, especially at escape velocity. In addition, there's no possible way to send up the millions of rockets needed to send our trash out from Earth when you consider the manufacturing costs (for no economic gain) and the limited fossil fuels available.
where Allen Shephard. Jr. went in 1961.
About the only use for this would be tourism. The military does its own research and the microgravity research can be better done on ISS, which is subsidized and already in place.
If I understand your friend, he proposes converting the upper stages in space. This would be difficult. You would need to rip out the machinery. Then if humans are to go inside, decontaminate them of any hazardous chemicals, left-over fuel, etc. Then install the equipment to turn it into something useful, which has to be brought up separately. Considering the difficulties of working in space, it is probably easier to do all of this on the ground.
You don't need to imagine. The price has already been fixed by the Russians for $20 million.
and the 2% failure rate which would spew toxic waste over a large area. No one wants to take the political, economic, and environmental chance on that, and rightly so.
It's a better method to find ways to deal with garbage here at home, like producing less...
Actually, there is a market for it. Two, in fact. First, low-G scientific experiments. Second, satellite launches. They already do this with the shuttle---using a booster rocket to kick the thing into a higher geosync orbit. Think of the RSV as a reusable, manned launch platform for satellites. If it could be done in a way that was totally reusable without major refurbishing, it would be a lot cheaper to launch than a Saturn V or something.
:-)
Of course, the (disposable) booster stage would be much bigger and more costly than what they use now, but it still might be a win... emphasis on might.
Good point about the possibility of using a disposable booster stage to boost the payload out of the sub-orbital trajectory and into an orbital one. However, I share your skepticism that it could be done cost-effectively. After all, you've just effectively reduced the payload-carrying capacity of your suborbital vehicle by about a factor of 20 or so, as you need to, instead, carry a booster capable of lifting a (much smaller) payload from your suborbital altitude up to a specified orbital one, and then "circularize" the orbit, as well. All that maneuvering takes energy, and it's quite likely to require significantly more than an equivalent "disposable" launch system would use to acheive the same objective.
Also, by including a disposable booster, the complete "launch system" is no longer "reusable", is it? Of course, neither is the current Shuttle, considering the disposable nature of the External Tank.
how about US to europe in an hour?
Imagine getting a package that was sent from the other side of the world that morning?
For military applications, you could station troops at home, but be able to deploy them in an amazingly short period of time.
The Kruger Dunning explains most post on
Um. You do know that the only reason that the Space Shuttle isn't fully reusable is that Congress wouldn't pony up enough development (not research) budget at the key point in the architecture cycle? That there existed and exists an entirely plausible design based on the same basic technology that the Shuttle uses?
My degree isn't in aerospace engineering
Ok, perhaps you didn't. So why are you stating that something can't be done when you don't actually know about it?
-WolfWithoutAClause
"Gravity is only a theory, not a fact!"Roadblocks:
- "rocket culture" at NASA
- "astronaut culture" at NASA
- materials science issues are quickly disappearing
- some probability of catastrophic (not deadly, just catastrophic) failure early on. must be budgeted using real-options analysis.
- 10-20B USD. This can easily be funded without "coalition" help. The US would soon own space like never before, as ESA's rockets would quickly look outdated.
- Defense concerns - the notion that a space elevator is vulnerable to, say, hostile fighter planes.
SPACE ELEVATOR NOW - it's good science, it's good policy.it would be nice if you understood why military equipment cost so much, but you here some number spouted by a news source, and let you ignorancew conclude that it was a waste.
go to any manufacturing plant, and order 50 of a specially designed screw, and see hom much it costs, per screw.
The Kruger Dunning explains most post on
s/Clitter/Clipper/g
Is a simple cut-and-paste that difficult, Beavis?
20 January 2017: the End of an Error.
Has there ever been a business case (ie profit) for ANY manned spacecraft at all? If NASA has failed to create one even with billions in taxpayer money, it follows that a huge leap would be required to fly one for profit. So I don't find the article too surprising.
ssshhhhhhh... ;)
The Kruger Dunning explains most post on
I'm in North American and my hair dryer is 1875 watts, so there's definately no 1800 watt limit on them here.
:).
And yes, I like it at that level. Takes all of 45 seconds to dry my hair (if that). I'm in a rush in the morning and it gets the job done
Then sit back and see what kind of aircraft carrier sized behemoth vehicle they come up with...
Once you're above, oh, say, 40,000ft or so (IE, and minute or two after launch) you're above 99% of the air.
Yes, and how much fuel do you burn in that first minute?
Tarsnap: Online backups for the truly paranoid
You've either been seeing too much Futurama or not enough. It's been done already - picture
HIV Crosses Species Barrier... into Muppets
So this gives another route there- the Ruskies sell a whole bunch of space tourist seats, and grow the market organically. Now, once they've tapped out the multibillionaires, the only way to grow is to cut the launch price; to attract the slightly less rich. The Ruskies are making a pretty decent profit on this at the moment, and if they up the launch rate the cost of the vehicle comes down at about 15% cheaper every time they double production. Now the biggest market is down at about $100,000-$500,000 per trip end, and the Ruskies are well placed to capture it and make a reasonable profit- their kit is cheap, and good.
Of course as they prove out the market, it means that competitors will be able to borrow money to start up their own businesses; at the moment few investors believe that the market is real.
So I don't believe that the RLV market is necessary to actually get us to full-on orbital tourism for the (well-heeled) common man. But it's still a good idea, and I hope it works out too.
-WolfWithoutAClause
"Gravity is only a theory, not a fact!"Obital brothels seem like the most likely way to make human space flight profitable, sounds like a winner to me.
The Orbital Sciences Pegasus already does this. It uses an L-1011 airliner to carry the rocket to 40,000ft where it's dropped and it gets boosted to orbit. Air launching does limit the size of the dropship. Its payload is only 1000lbs to LEO.
I doubt we'll have stable colonies on Mars or the Moon to ship people off to before this becomes a problem, although perhaps we'll discover more ways to make things out of easily biodegradable material and recycle what we can't using fewer resources than we'd expend burying or expelling into space the stuff. But the idea will almost certainly look attractive and feasible at some point.
Oh, and your defence concerns are bunk.
Any sufficiently advanced technology is indistinguishable from a rigged demo
--Andy Finkel (J. Klass?)
...like an aeroplane, but a lot faster.
Check it out at http://rc.explosive.net/rutan
- jason
You don't need to link this stuff for that. Just read your email and send money to all your correspondents.
Killer Apps:
...?
... within a few hours and then have Satellite One return a day, a week, ... later without having to reposition more expensive satellites.
If the Rutan vehicle only costs $20,000,000 to develop and build, compare that with a $4,000,000 Cessna Citation or a $1,000,000 Eclipse. Jet Setting will become passe.
If you can get instruments and people to the edge of the atmosphere and back within a few hours, consider how might that change high altitude research? How might that effect research on high altitude lightning, ozone depletion, atmospheric pollution, weather,
If you can get SpaceShipOne to the edge of space, you can get Satellite One to take a picture of that emerging volcano, that train accident and resulting chemical plume, the earthquake,
Mod Parent Down: Unimaginative.
--Mike
Let's not forget that there are a number of potentially viable alternatives to strapping oneself to a controlled chemical explosion and hoping it gets you where you want to go.
The mass-driver concept pioneered by MIT is one that could provide continuous access to near-Earth orbits with clockwork precision. It would be expensive to build and run, but once running would reliably put anything we want into orbit, continuously, twenty-four hours a day.
Another possibility is the laser-launcher. A rocket fueled simply by tanks of water would be heated by a bank of ground-based lasers: the resulting superheated steam would lift the vehicle into the desired orbit. The energy to propel the spacecraft would come from the source powering the lasers, not from any chemical fuel in the vehicle itself. This system would have the advantage of not requiring massive acceleration: laser power could be modulated to provide a comparatively gentle takeoff.
The irrational focus on self-contained launch vehicles is the problem: there are ways to get the required kinetic energy to the vehicle without an on-board fuel supply. Granted, it might take a nuclear power plant or two to run either of the above options, but that's a lot cheaper than building even a single space shuttle, much less developing and flying the current crop of pie-in-the-sky alternatives. Current estimates put the cost of a single space-shuttle launch at 1.5 billion dollars (I suspect that's conservative.)
And hey, when one of these gound-based launching systems isn't boosting spacecraft into orbit, it can be connected to the local power grid to light homes and businesses. Sales of power to the local utilities could be used to help offset launch costs.
The higher the technology, the sharper that two-edged sword.
I say we take the aerospace guys and mix them up with the guys who build the nuclear aircraft carriers and submarines.
/give flight
/give speed
/g_gravity 0
No, lets swap the aerospace guys with 3D game engine designers:
~
Esc.
# init 5
Connection closed.
Oh...
We have yet to make a nanotube that is a milimeter long. The space elevator needs millions of nanotubes that are 50 miles long each.
I'm wondering if the right tack is to just make boosters cheap. It seems to me that it is fundamentally difficult, considering the requirements for reuse and reentry survivability, to make any sort of SSTO cost effective given not only today's technology, but, tomorrow's as well.
Instead of trying to solve the hard problems via a pseudo commercial program, invest instead in the basic research for things like material sciences so that reusable space materials might be mass produced for other applications, driving down the cost of space.
In the mean time, we should be looking at how to simplify and reduce the construction cost of rockets so they can be made cheaper - since they are throway, and, while we are at it, if we can't keep the space "capsule" itself from being throwaway, at least design rack mounted stuff so all of the expensive avionics can be swapped out into another shell.
This is my sig.
True, and I apologize if my post's brevity was somewhat ill-considered. My oft-cited reference was to a more generic product purchase. However, that is not the focus of this discussion. I do see your point as regards governmental contracts, but I believe that the private sector is better able to change the nature of the vehicle from experimental to commercial. This would be done more efficiently in a competitive multiparty environment than in a governmental contract (and thus primarily bottom line)-oriented one.
It is possible to reliably terminate aramid (Kevlar) fibres at around 99% efficiency, in production.
I know, since my workmates developed the idea, and I did the calculations for the necessary hardware.
You need careful control of the way that the hardware and the fibres move under load. For the electrical engineers here, it is essentially an impedance mismatch problem.
We replaced a technique that could reliably hit 65%, in the same space.
Cool, let's bet the farm on technology that hasn't even been developed yet! Maybe we can use cold fusion to power it. Seriously, we should be using the technology we have now, and funding the development of new technology.
How we know is more important than what we know.
In short, the difference between the amount of energy you need to get into
orbit and just into space is a factor of 25
Was there not a smooth progression of increasing capacity rockets from the
V2 era of suborbital rockets up to the first orbital rockets? What would
preclude the same from occuring this time?
Realistic reusable designs are usually not staged designs, because it's hard
to recover and reuse the first stages.
The shuttle first stage (SRB) is reusable. The second stage (SSME) is also
reusable. Only (I realize it's a big part) the external tank is not reused in some
way.
The book "islands in the Sky" by Schmidt and Zubrin presents a viable alternative to using full-scale SSTOs and other launchers by applying existing high-strength materials such as spectra or kevlar. The concept is called a "hypersonic skyhook". *Unlike* a full-sized space elevator, it only needs to be twenty times heavier than the load it lifts into a permanent orbit.
Very briefly, if a cable (with a center of gravity at an altitude where the orbital velocity is ca 5,5 km/second) extends down to ca 200 km (where the orbital velocity is ca. 7.5 km/s) it means you can let a humble* suborbital vehicle latch on to the cable end. In an equatorial orbit, you get an extra 0.5 km/s free of charge.
You only need a vehicle able to reach a velocity of 5 km/s and hover for half a minute while locking on to the business end to the cable, after which it can let the cargo module go along with the hypersonic skyhook.
This is doable with current technology, and could be done with a fraction of the money that is spent on "white elephants" like the ISS.
(*=By "humble suborbital vehicle" I mean the difference between 5km/s and 7.5 km/s means a reduction of size, cost and complexity by several orders of magnitude, compared to a SSTO like Venture Star)
Yours Birger Johansson
I already wrote a comment about this under the new launch vehicle topic, but it seems to be a better fit.
Those who haven't done so should read John Walker's (yep, the guy who wrote AutoCAD) paper written ten years ago on a different approach, one that *will* reduce the cost of spaceflight, and prove one way or the other if there is really enough commercial potential in space to build a sustainable space economy.
Here's the link to the paper: A Rocket a Day - Keeps the High Costs Away
Note especially how there is valid historical documentation to support the viability of this aproach - it's not just blowing hot air, we have hard economic evidence that this both is doable and affordable.
It's time to kill NASA and do this right. What are we waiting for?
"The future's good and the present is nothing to sneeze at." - Roblimo's last
3 minutes! Cool! That's gives me time for a cigarette afterwards, too!
The problem with incremental development of RLVs is that there's a huge leap between the size and difficulty of putting something into space
for five minutes (as in the current X-prize contenders) and putting it into orbit (as in the shuttle).
I might point out that DC-X and any potential follow-on offers an incremental development path for a SSTO RLV. Fly a little, tweak a little, fly a little more, tweak a little more. This was one of the suble problems with the VentureStar proposal, everything had to work right, first time, which meant they had to overdesign the vehicle, which lead to its weight problems, which utimately lead to its failure.
This being slashdot, please don't mistake this as argument, but I'd love to see some more extensive sources on this.
Well, we certainly won't be asking you to design any Martian landers! ;)
When you lose something irreplaceable, you don't mourn for the thing you lost, you mourn for yourself. - Harpo Marx
Basically capital has failed to open space as a frontier due to capital welfare in the form of protection of asset concentrations paid for out of taxes on things other than asset concentrations themselves.
The Coalition for Science and Commerce's work on space policy reform and fusion policy reform led to the realization that capitalization of technology required a radical restructuring of the tax code.
The result was a white paper titled "A Net Asset Tax Based On The Net Present Value Calculation and Market Democracy". Essentially the biggest economic problem civilization faces is the fact that those who acquire wealth can buy political favoritism in the form of taxes on everything _but_ wealth itself. This results in everyone paying the cost (in blood and money) of defending the legal rights of asset concentrations that are untenable militarily or morally. Stated another way: Wealth is not income. Its possession isn't protected for free. That's why taxes pay for police and armies and should be based on possession of wealth rather than its transfer (or its creation).
The fact that welfare for capital is an inescapable feature of existing political entities has created the wrong kind of economic heirarchy in the world at the wrong point in history. The insanely zero-sum mentality infecting the leadership of the world, while solar energy streams past the Earth in quantities orders of magnitude over what we could even conceive of using on Earth will be investigated by future historians as the only worth-while subject to understand of this era.
Here are the important excerpts from the aforementioned 1992 white paper:
The government should tax net assets, in excess of levels typically protected under personal bankruptcy, at a rate equal to the rate of interest on the national debt, thereby eliminating other forms of taxation. Creator-owned intellectual property should be exempt.
In the case of technological frontiers, this problem is solved by limiting the patent claims to 17 years. An inventor can sit on an invention doing nothing with it for up to 17 years, but beyond that time, its use cannot be inhibited by the inventor. In practice, most inventors are so eager to see their invention brought into widespread use, they endanger their own claim. The patented technique is unique among frontier claims in that it's use is not inherently limited -- techniques are not "resources", and in that it is truly the creation of the inventor -- not an emergent phenomenon of civilization and nature.
But in other areas, such as radio frequency and orbital slots, the analogy with frontier "land" is almost perfect.
The NAT, unlike George's land tax, makes it possible for the government to open up all frontiers to private claim and development. Claimants must simply define and register the nature of the property rights that they wish to claim so
Seastead this.
An interesting page is NuclearSpace.
The external tank is a nothing more than a drop tank. Not all that different than the tanks used on the P-51 Mustang and the B-58. It is not most of what gets the shuttle into orbit. It is just a big honking tank.
Yes the shuttle is a reusable vehicle. The higher the profromance of a vehicle the greater the maintenance required. Other vehicals need to have there engines overhauled after each use Top fuel dragsters, Stock cars, Indy Cars, F1 Cars... The Shuttle is not a commercal space craft and needs to be replaced but it was not a diasaster or a bad idea. Just over sold and under funded. It was supposed to be part of a system. The Shuttle plus a space tug and a Space Station.
Only the Shuttle got funded.
Do you think if we all chipped in, we could buy Darl McBride a one-way ticket?
The problem with getting the government to do it is that you end up with NASA.
The capitalist argument is that business is the best way of generating actual prosperity, and at some point enough people (or one person) will donate disposable income in the direction of space travel.
Their chosen instrument might be government, but it might not. The chances are the individuals concerned will own large chunks of a company and will use that or another company to do the job.
It could best be summarized as: "You can't get to orbit by climbing successively taller trees."
Human genome = 3 billion base pairs = 6 GBit. Windows + Office = 20 Gbit. Which is more impressive?
The real problem is chemical rockets. They are very useful for launching unmaned space vehicles like communication satelites, space telescopes, and deep space probes. But they are far too expensive for launching human beings into space.
That is because devices like communication satelites can be designed for the environment of space, while human beings are designed for the surface of planet earth and so to keep them alive you have to bring along an enormous weight of things to support them.
It is also because satelites and probes can be designed to do things that are useful in space, like relay radio waves, while the things that humans are good at, like looking around a physical environment to find something, and going and getting it, are useless in space. That is why the only important scientific advance that has come out of 40 years of manned space travel is the moon rocks, it is because walking around on the moon looking for interesting things is so similar to what the human body was evolved to do as hunter and gatherers.
What is needed is some radical new technology that makes it effiecient to put men in space, and in particular to get them out somewhere like to astroids where they can do something economically valuable like mining. NASA should stop wasting tens of billions of on chemical rocket manned space travel, and instead spend it on lots of possible new technologies. The payoff in the long term would be far larger
Maybe we shouldn't be trying to "made it financially" and maybe we should be trying to save the human race and get another planet colonized ASAP.
M@
Krispy Cream is people
Put the reactor inside the rocket. Use it to heat the water directly.
1) You can launch from anyplace.
2) You can pick up fresh reaction mass pretty much anywhere, including far away from earth.
3) The two above mean that you could make landfall on places too uncivilized to have a laser, such as Mars, and then take off again.
4) Your nads aren't in the vicelike grip of whomever holds the "off" switch planetside.
The only difference between a ballistic and an orbital trajectory is tangential velocity. But you knew that.
There *is* an incremental development path to orbit. It goes from the X-Prize / microgravity / weather-monitoring straight up / straight down shots through ballistic trajectories, each one getting more and more hang time (higher, faster) until you're in orbit.
Why would you want to do this? Inter-continental travel. The idea's been talked about for decades. Coast-to-coast in 30 minutes. Across the Atlantic in 45 mins. Pacific rim in 90 minutes. All you have to do is fly a (sub-orbital! Ballistic!) trajectory higher, faster than we do now. That's your incremental path. Once you can go halfway round the world on one you've almost got an orbital trajectory.
Initial estimates were that an Orion launch would inject enough radiation into the air to kill ~10 people. The pulse unit designers thought they could get that down to 1 with some work. Before that number freaks you out, consider the crap that a shuttle launch spews. Chemical launchers aren't exactly clean.
"Seven Deadly Sins? I thought it was a to-do list!"
Your energy-cost numbers are far too low, Dr. Zowie! The megajoule-to-100 kilometers energy cost is for one kilogram, not one person.
Here's a fun way to think about it. For a person to fly from Seattle to San Francisco, 900 miles, in a jet with a 10-to-1 glide ratio, will cost as much energy as lifting the jet to an altitude of 900/10 = 90 miles! To see why, just imagine pushing the jet along a 900-mile highway in the sky, a highway with a of 1/10). At an energy cost of, very roughly speaking, half my the person's weight in jet fuel (jets get about 50-90 miles per gallon per passenger).
No problem. Check out the NASA history on the subject; it's reasonably good.
-WolfWithoutAClause
"Gravity is only a theory, not a fact!"Actually acceleration isn't the problem. It's still being able to accelerate when drag in not a deturmining factor. Most modren jets, in the absents of friction, could get to orbital velosity before hitting the ground, if they got a lift to 100,000ft. the problem is lifting all the fuel and still being able to fly. I believe that a truely reusable lanch viechal will come only when the transition from conventional powered flight to orbital flight is possible. For a start however I still think a 2 stage system where stage 1 is a large plane and stage 2 is rocket is an underapricieated solution.
JFMILLER
Strive to make your client happy, not necessarly give them what they ask for
Anybody know of a geek like us with a few hundred thousand they're willing to blow on a rapid buildup for the x-prize?
If so, let me know. If I could find a backer, I have a plan. downes_n@REMOVESPAMMENOWbellsouth.net
Karma Whoring for Fun and Profit.
Once upon a time the USA never had a reputation for doing things on the cheap. But today, it looks like they are trying to do everything on the cheap. (Iraq?) Seems like Washinton has been invaded by penny pinching accountants, or is it body snatchers, I cant remember.
A suborbital flight is short, expensive, and not very interesting. A trip to Mir was a real experience, but suborbital flight? It's like a really good roller coaster, with a really expensive ticket.
It's possible right now to charter the "Vomit Comet" KC-135, and experience zero G for a minute or so.. You even get to unstrap and move around. Very few people do this. Penn and Teller, the magicians, did once. That gives a sense of the size of the market.
Nuclear Thermal Rockets are the only real hope for SSTO. The challenge is doing it safely.
Third, Bombers.
A one-ton tungsten sphere dropped from suborbital altitude will hit the ground with more energy than any chemical explosive, without the other nasty side effects of nukes.
Needless to say, the USAF already has vague plans to spend a few jillion dollars on this.
In the last two decades we have seen NASP, Delta Clitter, X-33, X-34, VentureStar, Roton, and others come and go, Wow, I missed out on that one. I can't believe they couldn't find a viable buisness case for it.
Sure but I was only talking about vessels that can reach Earth orbit. And you really would not want an atomic powered space vessel launching directly from Earth. The risk of widespread radioactive contamination upon an accident such as happened to the space shuttle would be enormous.
Nah. A "pebble bed" style reactor becomes inactive and safe when scattered about. The "pebbles" are heat and impact hardened and would survive an explosion intact. Contamination would be minimal, probably less riky than the shuttle's poisonous fuels.
Also, a nuke rocket is much less likely to blow up. No explosive fuels.
The author says that suborbital RLVs, like what Carmack, Rutan, and the other X Prize contenders are working on, will create a business cycle that will eventually lead to orbital vehicles.
So basically we just sit back on our asses and wait for a business to evolve so space exploration is profitable? Doesn't sound like true science exploration or engineering to me, just a bunch of people who only look at it for the dollars and cents.
No, actually, that's not true. Jet fuel has about
the same amount of energy as gasoline, and it's just not enough to supply the kinetic energy needed.
Where most people go wrong is that high speeds are pretty counterintuitive: the amount of energy goes like the square of the speed, so doubling your speed quadruples your kinetic energy. Accelerating your car to 60 mph requires about a megajoule (one snickers bar). Accelerating it to 600 mph in the absence of friction would require about 100 megajoules (ten snickers bars, or about a gallon of gasoline) -- that's about the level of kinetic energy that jets support. Accelerating your car by another factor of 10 to 6,000 mph would require 10,000 snickers bars, or about 100 gallons of gasoline -- assuming the same efficiency as your engine gets driving you around town. Rockets are considerably less efficient, so getting going that fast with a rocket engine would require more like 1,000 gallons of gasoline -- except that fuel in those quantities would affect the mass of your car, so you have to spend even more fuel to accelerate the fuel you burn at the end. All told, getting your car up to orbital speed with rockets would take something like 5 or ten thousand gallons of fuel.
Clark Lindsey at HobbySpace has some detailed suggestions for how NASA's shuttle budget could be re-tooled to promote the growth of private space industry, and still accomplish NASA"s human spaceflight goals. He advocates sending the remaining shuttles to museums, purchasing launch services first from the Russians, at least through 2004 when new commercial launchers should be available, and investing in the suborbital RLV industry mentioned in this space review article.
Good ideas there... any chance of it happening?
Energy: time to change the picture.
Which reminds me of the old one about the Polish moonshot that fell back to earth from 400 feet when they ran out of coal.
penny pinching accountants, or is it body snatchers, I cant remember.
Worse: we've been invaded by consultants from big accounting firms.
-- $G
There's simply no market for delivery vehicles that always bring their cargo back, and never leave it at the destination!
True, but a sub-orbital vehicle could make for a very fast way to get from point a. to point b. on the surface of the Earth.
The higher the technology, the sharper that two-edged sword.
The Pegasus is a small solid rocket launch vehicle that is dropped from an L-1011 - having the inital aunch at 40,000 feet and Mach 0.85 does help a wee bit. Remember, for a given Isp and payload, the propellant mass goes to the e^(delta-V) - slight reductions in delta-V can give significant reductions in propellant mass.
Launching from 100,000 feet and Mach 3 will help even more - there was a proposal to build the third B-70 to support this kind of mission. There are also a couple of advantages of a very high altitude launch - for a given altitude, the velocity will be lower than a ground launch (lower aerodynamic pressure) and the nozzle can be configured for vacuum. The latter allows for a good expansion ratio with moderate pressure - smaller pumps for liquids or thinner cases for solids.
In some ways the current shuttle was designed backwards - the thing that goes into orbit is often the smallest and presumably cheapest component of a launch vehicle. Designing the final stage to survive re-entry adds a lot of weight - both for thermal protection and for fuel to de-orbit the sucker. It would make more sense to recover the most expensive part of the LV, especially if it travelling slowly enough that thermal heating isn't a problem (and that's pretty much how the Shuttle SRM's are treated).
There have been a couple of proposals for a re-usable booster for the shuttle - one would have brought back the F-1 engines and used jet engines to allow a fly-back to the launch site (jets should work fine on RP-1).
A Shadeless room is a brighter room.
how about just the "I've had sex club"?
You don't realise that since fifties there is
the killer (how double-sensed word) app for certain kind of suborbital vehicles.
These vehicles are named intercontinental ballistic missiles, and their application is to carry several tons of cargo accross the ocean order of maginitude faster than jet planes can do.
Ther is other almost as murdereous application of the same vehicles - delivering same several tons of goods to the given point of globe with several meters accuracy.
If techology can do something with acceleration and make thing launch and land in the common airport, it can be economically feasable.
RLVs aren't enough. To get the heavy infrastructure needed to bring the kind of space facilities (housing, industrial parks, labs, support facilities) which will make space industrialization and full-time space-based research by scientists going to work in labs up there every day, space tourism other than quick up and down trips, and to make powersats workable at a reasonable price per KWh, we need something cheaper than rockets.
We need to bring the price of getting freight into orbit to dollars a pound, not thousands or even hundreds of dollars a pound.
The candidate technologies are earth-to-LEO railguns and nanotube-based space elevators. Probable price: tens of billions of dollars.
With a way to get freight into orbit (housing modules, machine tools, semiconductor fab equipment, etc.), the number of probable passenger trips into orbit change dramatically, though with the elevator running, the trips change to zero because practically all traffic uses the elevator. As I see it, the railgun is doable with extensions of known technology, the elevator may be a lot further off, depending on research progress.
Given the short horizons and risk-averse business climates, the only way we're going to get railgun launch facilities together or a space elevator is via government sector investment. Of course, the US is too busy playing military games in the Middle East to get the last few hundred megabarrels of oil to think about big, ambitious projects.
So a requirement to work in the jobs beyond earth atmosphere when a skyhook project is finally built may be. . . being able to speak Chinese, one of the major India languages, or it's remotely possible that the EU will get its shit together to do this.
One thing we do know. The oil is going to run out. The question is whether we do this now, while the question of paying for it is a matter of slightly higher taxes, or when the oil is visibly running out, when the choices are do it whether we can afford it or not or watch technological civilization go down the tubes.
Tech Public Policy stuff
Please take away the troll mod for this parent comment :)
An Education is the Font of All Liberty
It would seem to me that companies like UPS, FedEx, USPS, etc... would find the ability to ship from New York to Hong Kong in a couple hours a significant incentive to start investing in this field.
Is it possible, say within the next ten years, to develop a suborbital shipping vehicle that can carry enough payload to make it worth thier while?
The idea is that as the companies compete to build systems that can handle even heavier payloads, out of this should emerge a system that can also handle orbital flights with a bit lighter payload.
Is this a reasonable assumption?
McDoobie
I think there was a space.com article a while back about the costs of the new NASA reusable vehicles. It was the author's opinion that there were too many pilots at NASA and not enough 'spacemen'.
Which brings up the point, why does it have to fly in a conventional sense like an airplane? The common adage about the Shuttle is that it's a 'flying brick' controlled by computers, so why even pretend to have a pilot 'fly' it? An Apollo era capsule would be sufficient for space station 'lifeboats' and I'm surprised someone hasn't tried reverse engineering the Saturn V for launching big payloads. If the launchers were cheap, it wouldn't matter much that they were disposable...like razors
the good ground has been paved over by suicidal maniacs
Will some start focusing on that. With a bit of time and money it could happen. THe carbon nanotubes are starting to be developed. Quit using the shuttles. Stop developing another, leave suborbital to the x-prize and start looking at the space elevator. We know thats the only way to go.
-- Karma Karma Karma Karma, Karma Chameleon - Boy George
I think your math is wrong. Maybe 50-90 gallons per mile per passenger. But that seems a bit too high.
i ly/technic al.html
.015gpm/passenger. .015 == 66.4 mpg/passenger.
:-/
e ch nical.html
Take the 747-400 for example:
http://www.boeing.com/commercial/747fam
Max Fuel Load: 57,285 Gal US.
Range: 7,260 nm.
=====
7 Gal US. / mile
With a passenger load of 524 people you get
1m /
Guess your math isn't wrong.
(miles * passenger) / gallons
http://www.boeing.com/commercial/777family/777t
Whereas the 777-300 gets 72.4 mpg/passenger.
Hmm... learn something new everyday.
Baka...
Key to the space is off-the-shelf technologies plus complete de-regulation. One thing everyone tends to forget is NASA pulled down its shuttle operational $/kg ratio by proposing doing every govermental/military/science and commercial launches which effectively locked everything down.
You can't launch even a nut&bolt pair to the space using a non-US organisation if it originates from good ol' USA without going through lots of red tape. Lots of companies like Sea-Launch does this by doing all sorts of strange things.
What if...instead of the government chanelling untold billions in to NASA programs that are rarely completed and that the public has no confidence in, they took 1/3 of the NASA budget and used it to fund "contests" like the X-prize. A few billion would get the attention of a lot of companies around the world. Spend 20 million, win a billion, hell of an ROI.
Maybe have a stipulation that participants relinquish IP rights to their designs to further the world's space push.
I have to say there are some serious environmental issues with his plan but it gives an interesting insight to the whole "launch costs" problem.
Aim it at the sun == bye, now!
:)
The only problem now is convincing everyone that
a) This isn't _really_ incineration
b) The sun is not in their back yard
and we should be sorted
Rational thought is the only true freedom
There is other CHEAP technology that can provide space launch capability.
1. Air launched SpacePlanes. The X-15 program could have allowed a man to reach space MUCH EARLIER than Glenn did via purely a ballistic ground-based system.
Because the ground-based ballistic stuff ALSO had uses as ICBMs -- that was the system that got the nod!
2. Air launched from balloon -- this has been used for relatively small stuff at high altitude.
3. Second stage from Super Gun. The trouble for this is the second-stage and payload have to be resistant to intense initial accelleration.
No1 is usable for moderate (and human) payloads with current carrier aircraft. Even the Concord could be modified to serve for high-altitude, high-speed air-launching.
.
(David Bowman, EVA near HUGE Monolithic Win-PC in orbit around Jupiter) "My God - its full of Malware!"
"Lifting yourself up 100km requires about a megajoule"
Does that mean I could get into space by launching a doughnut powered stage from the underside underside of a hairdryer driven plane?
hmmm... clitoris....
Notably however a 747 holds more then 10,000 gallons of jet fuel and burns it at a rate of 1219 gallons per minute at full throttle. My point was that if a jet engin worked in the absents atmosphere that there would be more then enough power in any comertial jet to accelerate to orbital speed. the problem ofcourse is that one neesd fuel that will combust in the absents of envriomential O2.
The long and the short of it is 85% of the force needed to put the shuttle into space is spent lifting it out of the atmosphere while only 15% is used to achieve orbital velosity. If aerodynamic forces could be used to get even halfway to orbital altitude it would eliminate the need for a craft like the shuttle to use disposable rocket engins.
JFMILLER
Strive to make your client happy, not necessarly give them what they ask for
you better hope you win that battle... it's a LONG wait before someone can pick you up, ships are still very slow moving vehicles =)
This is of course assuming that the recon was not deployed until you were deployed, which would be insane, but consider this... what's the point of instant deployment if you still have to wait until the ships are almost there before you can deploy those "instant" troops?
Video meliora proboque deteriora sequor - Ovidius
Launching from 100,000 feet and Mach 3 will help even more - there was a proposal to build the third B-70 to support this kind of mission. There are also a couple of advantages of a very high altitude launch - for a given altitude, the velocity will be lower than a ground launch (lower aerodynamic pressure) and the nozzle can be configured for vacuum. The latter allows for a good expansion ratio with moderate pressure - smaller pumps for liquids or thinner cases for solids.
DARPA is currently funding a project called RASCAL (Responsive Access, Small Cargo, Affordable Launch) that would use such a high-altitude, high-speed aircraft to launch small (on the order of 100 kg) spacecraft into LEO quickly and cheaply. Earlier this year they awarded a contract to a startup, Space Launch Corporation, to continue design work on RASCAL. First flight is tentatively scheduled for 2006.
Jeff Foust
The Space Review
The problem with incremental development of RLVs is that there's a huge leap between the size and difficulty of putting something into space for five minutes (as in the current X-prize contenders) and putting it into orbit (as in the shuttle). That will make it difficult to evolve our way into a commercial space program.
If you attempted to go directly from an X Prize-class suborbital RLV directly to an orbital RLV, I would agree with you. However, there are intermediate steps along the way, notably suborbital RLVs with varying amounts of crossrange. Most of the X Prize vehicles are designed to take off and land at or very near the same place. Following generations of suborbital RLVs could be designed to travel downrange hundreds or thousands of kilometers, perhaps as incremental/scaled-up versions of X Prize-class vehicles. (Indeed, the X Prize organizers have discussed having, as a follow-on to the X Prize, a "Y Prize" that would require vehicles to also travel some distance downrange.) This opens up new markets, like rapid cargo delivery, and also pushes the designs of the vehicles closer to what's required for an orbital RLV. There will still be a leap from suborbital to orbital vehicles, but with careful design it need not be a huge one.
This incremental approach is also applicable beyond suborbital RLVs. Elon Musk's SpaceX has a similar incremental approach for its orbital launch vehicles, from the Falcon to the Falcon Heavy to an even larger vehicle that would use the two Falcon stages as upper stages. Note that Musk also has an interest in human spaceflight, and those requirements are being incorporated into the design of the Falcon and its successors.
Jeff Foust
The Space Review
Great, thank you.
A 747 holds several tens of thousands of gallons of fuel, but it also weighs perhaps a hundred times as much as your car. The fuel just doesn't have enough energy to get the plane up to orbital speed.
The X-15 didn't launch from a runway. Rutan's ship doesn't consume half its wet mass getting to launch altitude. The issue of fuel consumption reaching 40,000 feet is only problematic for single-stage-to-orbit and multi-stages with rocket powered lift-off.
-Hope
Hmm, Delta Clitter and brothels. Plus only copying the first page of the article
I think we've got ourselves a lame karma whoring troll
Very poor buisness logic in that story. Granted given current launch needs an RLV faces a problem in that if we had one tommorrow we wouldn't have enough work for it. However the logic of that argument is like saying in the day of Charles Lindberg had a 747 been available not enough people would be intrested in being able to fly across the atlantic. How many buisness models utilizing space transportation are deemed non-viable due to launch costs. How many new ideas might be born if cheap access to space were a reality ? The logic in the story fails to even discount the possibility of new uses for space instead choosing to focus on the current launch schedule and projected launch demand based on current launch capacities.
Just to give one concrete example take the telecom needs. Telecom stats are expensive. They are expensive to build because they have to last ( ie that have to be uber reliable ). This is because they cost a butt load to launch and backup launches are almost unthinkable. Now decrease launch costs to say the truly optomistic $100 a kg. for simplicty of agument and satalite designs need not be so intollerant. Expanding capacity ( IE stalite broad band ) becomes a non-issue. Most stalite launch demands are similarly governed, expensive launch makes for even more expensive development due the the fact you don't get second chances.
Changing the cost to orbit changes the entire dynamics in a way that simply can't be predicted. Perhaps the payloads will not be there... but just like trans-atlantic flight took off almost overnight once a suitable technology came around I imagine there will be an expansion of launch needs once a more viable and cheaper access to space becomes available.
Re-useable launch vechicles make obviouse finacial sense... the question is can we actually make one more than should we make one. If we can't then maximising one time use designs is the path to highest payload margins. If its possible ( and the case can be made ) then you do the math. A re-useable design that reduces cost to orbit has to cost more than is currently being projected to not be able to pay for itself... the catch of course is if it can truly reduce the cost to orbit enough. Having said that I grant the reality of the current launch needs means a system that sufficiently drops the cost of reaching orbit likely could not recoup its development costs without a corresponding increase in launch schedules except by comparison to what a launch would have cost without the new RLV ( IE phantom accounting ).
Arguing that the technology to build an RLV from one time designs is somewhat inaccurate. Granted some progress will undoubtably be made however there will be no enginerring imperitive to make a system durable enough to be re-used because any excess weight above and beyond what is needed for a single launch cycle will be spurious. Technology advances follow the engineering goal. Metal skin and honey comb composites in plane designs did not come about from pefecting wood and cloth planes, it was a direct improovment driven by the desire for faster designs that could sustain higher loads with less maintenence. If you want RLV technology then at some point you have got to aim for RLV's... not SLV's.
I don't ask you to be me. I only ask you not expect me to be you.
The forces on the "lasso" would be extremely high, quite possibly beyond current (or even any) material, although making the lasso quite long would spread out the kinetic energy exchange over a longer period of time, reducing the instantaneous accelerations on the payloads.
One possible application would be sending up payloads consisting of a booster rocket plus equipment; the payload would travel to say a lunar mining station, and the returning payloads would be mineral resources. If a similar system were used on the lunar end, in theory the only energy expended would be to compensate for frictional losses (plus the energy to "prime the pump" with the first payload); getting out of the gravity well would be "free". (Much like a hybrid Civic with regenerative brakes stopping and starting up again)
Of course, IANARS, but I would love to hear why this wouldn't work...
I also recall that the US ASAT system was launched from an F-15 - which would have been especially handy for targeting Soviet birds in the Molniya (sp?) orbit...
Looking at the comments posted, I would gather that most /.'ers wouldn't know a copy of Sutton if it bit them on the ass.
A Shadeless room is a brighter room.
> 10,000 gallons of jet fuel and burns it at a rate of 1219 gallons per minute
--Either you're crazy, or you missed a decimal point somewhere. There's no WAY a 747 could burn over 1 thousand gallons per minute.
Howard Dean staffer, anti-spam advocate.
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