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Air Force Wants Reusable Fly-Back Rockets
FleaPlus writes "The Air Force is initiating a pathfinder program to develop a first-stage rocket booster capable of gliding back to a runway so it can be easily reused. Lockheed Martin has already launched a secretive prototype, and a Cal Poly team has a prototype based on Buzz Aldrin's Starcraft/StarBooster design (video). The Air Force estimates such a booster could cut launch costs by 50% over the current Atlas 5 and Delta 4 rockets, and could also offer a rapid surge/replacement capability if combined with reusable spacecraft like the recently launched X-37B. Initial test flights are planned for 2013."
I hope they can come up with something that works out. This should have been done decades ago when it became clear the shuttle would always be an albatross.
If flying cars could be made to blow up the enemy, or even just humiliate them, we'd have flying cars. Not to take anything away from the folks at Cal Poly, but I'm still waiting for the next Teflon.
There are plenty of rockets which don't blow up... or at least shouldn't.
The current problem is that these rockets tend to shred themselves to pieces except for their fragile payload, and drop anything that is left into the ocean. This is considered by many to be a waste of an otherwise good rocket. Now, the feasibility and economics of repairing and reusing what is essentially a long tube filled with exploding fuel is a completely different story...
Good luck, engineers.
>> Standing on head makes smile of frown, but rest of face also upside down.
Boeing did a study of making a winged Saturn V first stage back in 1962.
http://www.astronautix.com/lvs/winturnv.htm
The payload penalty might be problematic. Also, you can't really cluster more than 2 flyback stages due to the size of the wings. If you could use a parafoil and land with skids, that might solve that problem and to be fair western rockets don't really use clustering (Delta IV Heavy being a notable exception).
Graham
Fifteen years of development by committee, and they'll start construction on something that looks exactly like the Shuttle.
Because this is pretty much exactly where the Shuttle started.
I stole this sig from someone cleverer than me.
We are using 2,300 year old technology... It's time to quit teaching what can't be done, so we can open up to what can be... The subject of propulsion, or mass and inertia would be a good place to start.. Right now our systems are as comical as the old Flash Gordon pointy tin can with sparks(ions?) coming out the back.
You can't do that, it's impossible!
Well, nobody told me...
“He’s not deformed, he’s just drunk!”
WTF, they launched a Cal Poly team? Where's the copy editors when you need them?
Every Kilo counts - there are no tricks, or move closer to the equator.
First stage mass makes little difference to overall performance because it doesn't have to be carried into space... if the first stage is heavier you typically just load more fuel to compensate, and fuel is generally cheap compared to the hardware in the first stage (obviously that's not true for the shuttle SRBs, which is another reason why they were a really dumb idea).
1) You shouldn't reuse rockets.
Yeah, you should, because if you use it once and it works, you know it will work again and again (see DC-X). If you build a new one, you won't know until you've flown it.
This of course assumes that the thing is designed to be flown and re-flown without a complete overhaul between each flight -- i.e. like airplanes not like current Shuttle technology. Or you build a new one for each flight, spend a fortune trying to inspect-in quality, and blow up one in thirty or so anyway. The latter is how missiles are designed, not a rational transportation system.
-- Alastair
Isn't the shuttle such an albatross precisely because reusability is so impractical?
Nope. It's because somebody goofed and they made the wings too big. As I heard it back then (caveat: didn't check it myself):
The shuttle was supposed to be a combined civilian and military vehicle, so the design budgets could be combined and the cost per unit could be brought down by building a bunch of 'em.
Civilian stuff mostly orbits equatorial and near-equatorial, launching eastward to get a boost from the Earth's rotation. This would be launched east from Canaveral, so crashes would be into the Atlantic. A lot of military stuff orbits polar or near polar, and doesn't get the boost. This would be launched south from Vandenberg, so crashes would be into the Pacific.
Without the boost from the Earth's rotation you get a significant reduction in payload capacity. There's a rule of thumb for computing this.
The shuttle lands as a glider. The wings are partly for steering it for cross-track on the way down. The farther the worst-case sideways distance from your orbital track to the landing site is, the bigger the wings you need.
For typical missions the Shuttle doesn't need much cross-range capability: You just wait for the orbit closest to going right over the landing site and go down then. This happens twice per day. You could get away with little stubby wings like the X-15.
But the military wanted to be able to run another mission profile: A polar, pop-up, once-around shot, landing back at the launch site. This would be for things like spying in a war or near-war situation, when you'd want to get the shuttle down with the info right away and also before the enemy could shoot it down. Problem with this is that the earth moves the landing zone out from under the orbit and you need a lot of cross-range capability to do it. So you need big wings.
So they ran a sanity check on whether the polar orbit was still doable with the big, heavy wings needed for this mission. They're heavy, and that weight comes right out of payload, so the payload capacity would be reduced and the cost-per-pound to low orbit raised a bunch. But it looked like the polar orbit could still launch a decent-sized cargo. So they went with the big wings.
But when they'd run the sanity check they'd applied the rule-of-thumb to the CARGO weight. Somebody had forgotten that, since it also ended up in orbit, the orbiter itself, along with the crew and their consumables, WAS ALSO PART OF THE PAYLOAD. So you have to apply the rule of thumb to the TOTAL weight: Payload, orbiter, consumables, reentry fuel, yadda-yadda-yadda.
Once they did the computation right it turns out that the shuttle would only have a couple hundred pounds of payload to polar orbit. No launching spy satellites for you! Oops!
So the military didn't end up using the shuttle (except for a couple equatorial shots testing some gear). They built their own big boosters and went their separate way. The Vandenberg shuttle launch site was demoted to an emergency landing site (so the shuttle could be landed if Canaveral had bad weather and then piggybacked to Canaveral rather than relaunched from Vandenberg). The military didn't buy any craft and the whole cost of construction and operation fell on the civilian projects, raising the cost-per-pound still further.
Bantam Dominique roosters crow a four-note song. Once you've heard it as "Happy BIRTHday" you can't NOT hear it that way
I think you gravely misunderstand and underestimate the rigors of rocketry. The stresses encountered are nothing at all like in your car or even a jet turbine. You're basically continually exploding gallons of fuel per second at very high temperatures and pressures. Right on the other side of the bell, you have turbopumps spinning at very high speeds and at cryogenic temperatures. Toss in the monstrous vibrations and stresses, sorry, you DON'T reuse the parts.
If a rocket flies succesfully, you know the design works, kind of. The engineering is at or beyond the bleeding edge. In the Apollo days there was a lot of fudging and kluging to get the F-1 to work, and the Space Shuttle is no better.
This is because this stuff is HARD. Materials don't get stronger or behave differently because they're in rockets. They're manufactured, designed and built by humans and are subject to the same limits as any other product,
Basically, you know the design works, you keep the design. And you build many many many rocket parts. You use those.
Sort of like Formula One motors. No one reuses them. Why not? No one cares. You build them. You use them, they wear out after 20 hours, and you build another one. Simpler, cheaper, better.
The new budget revives the NASA Institute for Advanced Concepts (NIAC), which is the part of NASA which previously studied space elevators. The NIAC was one of the parts of NASA which was cancelled to fund Constellation. Also, there have been a few Centennial Challenges related to space elevators, like the tether challenge and the beam power challenge.
Actually, take your pick:
Centuri SST Shuttle
Centuri Space Shuttle
Estes Orbital Transport
Or going way back:
von Braun Passenger Rocket (1958)
I was bitterly disappointed that the actual shuttle looked so . . . clunky.
They haven't figured out how the passengers can survive the Muzak for the duration of the ride.
Have gnu, will travel.
I think it would be a mistake to assume that. An orbital ship isn't fundamentally any more complicated than a passenger jetliner.
They're vastly different, not only in terms of what's under the skin (specially engineered components, ultra-hazardous chemicals, etc), but also in terms of economics. Jetliners are designed from the outset to be economical enough to make a profit, not to exceed physical performance goals. If Boeing can't make a jet that makes money for other people, then they drop the project, even if it's interesting. See the Sonic Cruiser for the latest example in a long line of them.
Private companies, by contrast, are just now taking the same approach to building rockets. And since NASA is a government agency... they're not concerned with profit at all.... then their priorities are performance and technical achievement. Cost has always far down on the list of NASA's priorities. Their in-house slogan during the Moon Race was, after all, "money is no object, but time is of the essence".
When NASA says that they're building something with economy in mind, they always fail in some way, because they don't really have the same kind understanding about economy as a business that lives and dies by profit. This is the main reason, even more than politics, that the Shuttle became so expensive, and why the Clinton Era "better, faster, cheaper" programs had so many spectacular failures.
I'm a big proponent of SSTO
I love the idea of SSTO, but it's the spacefaring equivalent of Cold Fusion; a modern day pipe dream at current technology levels. Lockheed couldn't even get it to work with the X-33, let alone with the VentureStar it was supposed to spawn.
Life is hard, and the world is cruel
maybe if you engineer it to the bleeding edge specifications that the space shuttle main engines were built to, but the thing is, you dont need to build them like that, you can build them to be reusable, and still get large amounts of payload into space.
How often it happens is a product of orbital inclination and orbital altitude, for a typical Shuttle mission it happens on average twice a day.
That's what the designers of the Shuttle thought too, way back at the start of the design process. Then they actually started doing mission analysis - and discovered how very wrong they were. It turned out that average of only twice a day could leave the crew stranded, unable to reach a safe landing site, for periods of up to eighteen hours. Not good in the event of a problem on orbit, and the only way to fix it was to add cross range capability (read: bigger wings). They also discovered that lack of cross range capability limited the choice of abort scenarios and limited the orbital inclinations the Shuttle could reach. All of this meant the wings started growing - big and fast.
Wrong. Shuttle capacity to polar orbit is notionally 28000 pounds. (Probably greater now with the reduced weight External Tank developed for ISS missions.)
Wrong again. At least one military Shuttle mission went into a 61 degree orbit. Several launched classified satellites.
Sort of like Formula One motors. No one reuses them. Why not? No one cares. You build them. You use them, they wear out after 20 hours, and you build another one. Simpler, cheaper, better.
SpaceX regularly test-fire their engines with full mission-duration burns, then use the same engines on their launchers. Their engines are designed for re-use, to the extent of avoiding ablative coatings and materials wherever possible. They've even been careful to design for immersion in salt water so that in theory they can recover first stages, give them a quick going over, and whack them back on the launch pad.
As someone who works in the space industry, I think that saying, "You shouldn't reuse rockets," is a rather blinkered and negative attitude. With that sort of stance, how could we ever improve the state of the art?
Pirate Party UK