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Airbus Unveils Its First Stage Reuseability Concept
schwit1 writes: The competition heats up: Airbus unveiled Friday its prototype design to recover and reuse the engines and avionics of its Ariane rockets. From the article: "The Airbus team concluded that SpaceX's design of returning the full stage to Earth could be simplified by separating the propulsion bay from the rest of the stage, protecting the motor on reentry and, using the winglets and turbofans, return horizontally to a conventional air strip. "We are using an aerodynamic shield so that the motor is not subjected to such high stress on reentry," [technical director Herve] Gilibert said. "We need very little fuel for the turbofans and the performance penalty we pay for the Ariane 6 launcher is far less than the 30 percent or more performance penalty that SpaceX pays for the reusable Falcon 9 first stage." Gee, for decades Arianespace and Boeing and Lockheed Martin and everyone else in the launch industry insisted it made no economic sense to try to recover and reuse the first stage of their rockets. Then SpaceX comes along and makes an effort to do so, without as yet even coming close, and suddenly everyone agrees it is economically essential to do it as well. Isn't competition wonderful?
Why reuse something when you can trick governments to pay for it again. That make perfect economic sense until someone reveals the fraud.
Silence is a state of mime.
If you just want to see how it works, scroll down to the video at the end. They don't really explain it very well in the text.
XML is like violence. If it doesn't solve your problem, you're not using enough of it. --AC
The idea that SpaceX "did not even come close" is ridiculous. It was the FIRST to operate on the principle that it was practical, and has twice now come very close to getting it done. In only... what... 4 tries? On a target far smaller than the continents aimed at by Russia and EU?
I find this whole announcement to be saying: "Yeah, us too! Maybe a few years from now."
It's not as much of a race as you might think.
From TFA, Airbus is going to be spending the next five years finishing Ariane 6. Then, AFTER they're done with that, they'll start serious work on reusability.
On the other hand, SpaceX is already flying the reusability testbed(s), and running the tests required to refine the software to the point that it words as intended.
So it looks like a race that SpaceX is pretty much guaranteed to win, what with the ten year head start....
"I do not agree with what you say, but I will defend to the death your right to say it"
So its basically the Vulcan concept, a detachable avionics/engine package at the back and an expendable everything else. I suppose its an improvement from what we currently have but not by much. The only real difference from Vulcan is that instead of being snagged out of the air by a helicopter it glides back to some location under some power. I suppose I can see why Airbus and ULA are going for such concepts, they should be pretty cheap to develop (though I am sure they'll try to squeeze every dollar they can out of their respective benefactors), are relatively low risk and will still let them justify big launch bills with tank/upper stage replacement. But if SpaceX can pull off a Falcon first stage recovery even a majority of the time they'll blow this and Vulcan out of the water. Fuel is cheap, replacing tanks and stages is expensive.
They may win as soon as July 22nd, when the Falcon 9 is scheduled to land at Vandenburg AFB. It'll be really interesting to see how 'reusable' the first stage is after the engineers have a chance to inspect it thoroughly.
This has the look of a paper concept that nobody's put any engineering work into yet. Some possibly show-stopping engineering challenges:
1) The air-breathing engines are dead weight dragged most of the way to orbit. And turboprops and turbofans are pretty damned heavy compared to rocket engines: for many applications, the weight of fuel and tankage is so much greater than the engines that engine mass is irrelevant, but that's not the case here. SpaceX's design makes use of engines that need to go to space anyway.
2) Looking at the videos, the design relies on folding propellers that deploy in flight. This is ... not an easy thing to do. I'm not aware of any aircraft larger than a duck that uses this technique, even on carrier-based aircraft where space is at a premium.
3) While rocket engines are pretty lightweight compared to turbine engines, it's still a lot of weight to fly back home. The video shows a flyback aircraft with very short stubby wings. In addition, the wings can't be asymmetric lifting airfoils or they'd push the rocket sideways during lauch: the have to be flat boards. The return vehicle is likely to have a very high stall speed, making landing a challenge.
4) The video shows no details on how this propulsion module is attached to the fuel tank above it. This is difficult: enormous fuel and oxidizer pipes need to pass through the nose of the propulsion module, along with gigantic clamps attaching it to the fuel tank... but this surface is exposed to re-entry heating on the flight back. How do you route plumbing and avionics through your heat shield?
"The Airbus team concluded that SpaceX's design of returning the full stage to Earth could be simplified by separating the propulsion bay from the rest of the stage, protecting the motor on reentry and, using the winglets and turbofans, return horizontally to a conventional air strip."
Interesting definition of "simplified" they're using. They're not even recovering the entire first stage, and they're basically bolting a jet airplane onto it to achieve that much. Propellant is as cheap as dirt, they're avoiding paying tens of thousands of dollars in propellant by instead paying for jet aircraft maintenance and operations and an entirely new set of cryogenic tankage and a substantial amount of aerospace vehicle structure for each flight. SpaceX is just making the first stage a bit bigger (and looking at things like additional propellant chilling to increase density) so it has the extra capacity required.
"We are using an aerodynamic shield so that the motor is not subjected to such high stress on reentry"
Thus solving an issue that SpaceX has already shown isn't actually a major problem...they have been regularly bringing entire intact first stages through reentry and down to sea level for some time now.
As for SpaceX not "coming close"...their second attempt actually brought the vehicle to a halt on the landing pad, though with mangled landing gear, and the reasons for the control issues during the final burn are well understood. They are extremely close...odds are quite good that their third attempt (in a bit under 2 weeks) will be a success.
>if X launches from Texas, is there a nice place to land the first stage?
I'm not 100% certain, but my understanding is that the plan is to, depending on the amount of extra fuel allowed by unused payload capacity, either fly directly back to the launch pad, or land on the floating barge to refuel and *then* fly itself back to the launch pad. Though I remember some talk about SpaceX leasing one of the more remote and durable launch sites at Cape Canaveral, Florida, so I imagine they plan to eventually land there for refueling rather than on a barge in the open ocean, with the associated much greater weather sensitivity.
It may seem kind of wasteful in terms of both fuel use and engine wear and tear (though I believe only one of the nine engines is used on the return flight), but consider that the first stage is about 45m tall (around 15 storeys), with an empty mass of about 25,000kg (approximately the maximum mass of a loaded 20-ft shipping container). The size means it's pretty much impossible to transport over normal roads, and the mass means that only the largest military cargo helicopters could handle it. And I would assume it's not designed to survive significant lateral stresses (no point in normal usage = wasted mass on structural supports = reduced payload), so laying it on its side to transport it by ship or truck would probably be a major challenge. So either you build and maintain a specialized transportation vehicle, or you just let the thing do what it was designed for and fly itself.
>How far downrange was the barge, and what is that far from TX.
I've heard 400km, though I couldn't give you a reliable source. And obviously that's fairly trivial to extend considering the first stage is already hurtling downrange at high speed when the second stage separates. If it simply "glided" down to to cruising speed, just maintaining high altitude (low air resistance) instead of actively decelerating, it could extend that range considerably while likely consuming even less fuel (obviously the fuel required for the return trip would increase, but that has no effect on payload capacity).
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Aircraft technology isn't stagnant by any means: a modern 777-ER can carry the same number of passengers 50% farther for a third less fuel than the original 747-100. But that just proves your point, that breathless Moore's Law comparisons are moronic when talking about airplanes, cars, rockets, and bridges.
I think you're talking about the Jason-3 launch. That's actually a couple launches away, though it'll be their first landing attempt on the West Coast.
CRS-7 is launching June 26th (bumped back a bit, probably to let them reshuffle things to account for cargo that was supposed to be delivered on the last Progress) from Cape Canaveral. They are going to attempt a landing...maybe on land instead of the ASDS.
They've also got a geosynchronous sat launch in mid-July with the first "enhanced" F9 v1.1...that might have the capacity for a landing, which previous geosynchronous launches didn't have enough performance to attempt.
Is the airbus project worth anything? I have no idea. But the more money thrown at this issue the happier I am really.
We need to get into space and we've allowed our space programs to atrophy.
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So they bolt on a pair of wings, add some propellers that have to be deployed from a casing that protects them during launch, oh and another stage separation event, a mechanism for separating the fuel tank from the engine.
And that's supposed to be simpler than some hydraulic landing legs and grid fins?
And carrying all those additions to space doesn't cost them any extra fuel?
That's my point. Progress happens in all fields of engineering, but computer engineering happens at such a radically different tempo that it's not a useful comparison.
Space, as it turns out, is really hard. There are two basic kinds of techological miracle: working with microscopic quantities of matter and energy, and working with vast amounts. Science fiction authors of the '60s assumed that mega-scale engineering would continue at the incredible pace set during the 20th century, but it turns out we were just getting to the hard part. But they drastically underestimated what we'd be able to do with micro-scale engineering.
But aviation has gone backwards. When I was young, anyone with a few thousand dollars to spare could fly across the Atlantic in comfort at twice the speed of sound, and military pilots in a close approximation to space suits would be flying above them at nearly twice that speed.
Now we gush about how new airliners save a few bucks on fuel so airlines can make more profit as they cram more and more of us into the same little metal tube.
Scaled already built a close air support prototype -- http://en.wikipedia.org/wiki/S.... The world hasn't beaten a path to their door to buy them. I agree that the legacy aerospace contractors are crooks, but competitive modern fighters are extremely complex in every domain -- structural, propulsion, avionics. Ask the Russians and Chinese how well their 5th gen fighters are coming. I respect Scaled but Spaceship Two is a LOT simpler than a 5th gen fighter and it is not coming along so well.
What's progress? Is progress defined in terms of how fast we can get a handful of millionaires from New York to Paris, or in terms of turning an ocean into an insignificant obstacle for average citizen of the developed world? Today's airfares are about a third (in constant dollars) of what they were when you were young, and there are six times as many people flying. Turns out that the ability to fly to Paris at Mach 2 was a pointless waste of effort and money. What that changed the world was the ability to get there for less than two weeks' wages.
The Skylab malfunction was with the Skylab module itself, not the Saturn V vehicle underneath it. "The station was damaged during launch when the micrometeoroid shield separated from the workshop and tore away, taking one of two main solar panel arrays with it and jamming the other one so that it could not deploy." -- http://en.wikipedia.org/wiki/S.... Your point holds though, just not the right example.