Slashdot Mirror
SpaceShipOne Back in Action
JoeSilva writes "After a 3 month wait,
Scaled Composites' SpaceShipOne is
back in the skies above Mojave! Not only is it patched up from a failed landing gear, it's got a 'thermal protection system' installed.
Looks like high temp insulation on the leading edges. Also they have a picture of it with 'the rocket motor for the flight 13p'. This was the 12th SpaceShipOne flight."
So does that mean that SpaceShipOne will be making a run for the money soon?
They have a "falling bathtub mode".
Wonder how much they could make selling rides on that thing.
--Phillip
Can you say BIRTH TAX
so what happened to flights 9 through 11? The flight log jumps from flight 8 (first powered) to this latest one.
this is the only real post so far and it gets a negative one?
At least with my telescope I could spy on them 8^)
A feeling of having made the same mistake before: Deja Foobar
WOOHOO!!!
Check out the test updates here.
AFAIK, these guys are the closest to winning the X-Prize- go team!!!
Any generalization is a stupid one.
A great set of photos (hopefully soon to be mirrored) is available here.
Looks like the flight was a few days ago (March 11) - why is this the first report? They're being very quiet about this. And how did Joe Silva track this down?
Energy: time to change the picture.
Uh. Twelve FLIGHTS before. All the same craft.
here a mirror for you to slashdot as well (indeed, i don't like the sysadmin) http://elektron.its.tudelft.nl/~aakeur21/slashdotm e/
The X Prize is NOT ABOUT LEO! It's about reaching 100KM, with at least 1 person, in a vehicle capable of carring 3, twice in 2 weeks.
Generally, bash is superior to python in those environments where python is not installed.
While you are there check out the Global Flyer It is just as cool in my book. The similarity in the designs of the craft are interesting. The idea of flying around the world on one tank of gas is pretty wild.
It's hard to believe that's how Micronians are made. Why don't we see it right now by having you both kiss one another?
I've been following the X-Prize work at Armadillo for the last year or so. If nothing else than for the John Carmack factor. They seem to have stalled lately, always reengineering their rocket motors and such. I'm still cheering them on anyway though I can't see them surpassing Scaled Composites at this point.
One bad monkey spoils the whole barrel.
"I'm probably camping in Death Valley this coming Thanksgiving..."
In Canada, we call it "Easter".
-
Of course, the project we have to compare it to is John Carmack's Armadillo Aerospace venture (since they have the decency to provide week-by-week status reports, which I consider manditory Monday reading). The folks at Armadillo are still working on getting their engines to light reliably (extra important since they're using five of them) and still haven't had anything like a successful test flight.
I dunno, man -- If I'm Carmack, I'm thinking it's time to really get at it if you're still serious about winning the X-prize. The SpaceShipOne folks seem to be putting them further and further into the rear-view. Which isn't to say they *can't* catch up; if the Armadillo team can get their engines lighting reliably, they should be about ready to bolt the thing together and start flying.
Man, this beats the heck out of money pits like the ISS, eh? Nothing like a little old fashioned get-the-prize competition to turn up some interesting stuff. Maybe a $100 billion prize for the first company to land people on Mars and bring them back ought to be next -- get the government to cooperate with permits and NASA to share their tech. I'd bet you'd see people there inside a decade.
Every year during my review, I just pray the words "slashdot.org" aren't mentioned.
Also, IMHO the ship looks like some high-school science project with way to much duct-tape with the leading edges done the way they have it.
It looks like it's only a small matter of time before they actually launch this thing into suborbital flight. I'm willing to bet that the two flights will take place by the end of this year. How I envy the chosen pilot for the mission...
I think that the work being done by Scaled Composites will prove very useful in the next few years. Where I thank we need to see a much greater effort is in the fuels to drive these kind of vehicles. With advances in physical chemistry we could see an improvement of 2 or 3 orders of magnitude. With those kind of fuels one could put a bottle rocket into orbit!
"Can there be a Klein bottle that is an efficient and effective beer pitcher?"
Apparently, Scaled Composites is one of two teams to have applied for a permit from the FAA to launch a spaceflight. The other is Armadillo Aerospace, run by John Carmack of Doom fame. It's interesting to compare and contrast the two companies. Rutan has a sleek ship with lots of cool round windows that launches from a funky big plane, and they have some good solid live testing. The Armadillo team's site really shows you the nitty-gritty of building something that flies in your spare time, with pictures of them welding engines together, making a crew capsule out of whatever they could find, and building a landing gear with some thick cable springs. I'm guessing that Rutan will win, but I'll hold out hope that the garage engineer can pull off at least some type of flight to give courage to that old entrepreneurial spirit....
I'm waiting for Carmack to respond to the space race. I'm also waiting for a release date for DooM3! :)
I am defenseless. Use your button. Mod me down with all of your hatred.
They better not have any more delays like that last one, if they want to win the X-Prize. The $10 million dollar prize expires at the end of this year, and a lot of other groups are competing for it.
I think we'll see some exciting new developments in space technology over the next few years. I'm confident someone will win the X-Prize,(which is more a PR bonus for starting a space tourism company than anything else) the Bush Admin wants to send folks to the moon or Mars (probably using nuclear propulsion), and it's all but a foregone conclusion that someone will try to build a Space Elevator soon.
If you'd read anything about the X-prize, or even the other posts in this thread, you'd know that the ships are aiming for a sub-orbital flight (for those of you who went to public school, that means they're not coming back from orbit at the end of the flight, either), and therefore no space shuttle-style thermal tiles are required.
The kinetic energy required to accelerate a gallon of gasoline to orbital speed is more than the chemical energy contained in the gasoline.
By contrast, "merely" lifting something up 100km doesn't require much energy at all.
So, er, no, leading-edge heat shields ought to be just fine. Fiberglass or carbon-fiber composites might even survive a flight or two without any shielding at all.
I'm not fucking trolling you.
Dick Rutan? Weekend Warrior? Hmm. Ever hear of the Gossamer Albatross? Voyager?
Mr. Rutan is FAR from a weekend warrior. All-week genius, in my book.
My bad. The Albatross was McCready, not Rutan.
Rutan and Scaled are prob the Ultimate Gargage Engineers. He's done stuff that "experts" called impossible for years.
/.ed)
The "early" kit planes he designed are still works of "art".
(bad news, the site is
Sho' nuff.
Praytell, exactly which advances which produce a 200x+ improvement in rocket fuels are you referring to, sir? Which brand new propulsion tech did the SpaceShipOne folks come up with? Or are you just talking out of your ass?
The mod who chose that probably thought he was karma whoring. Should have posted it as an AC.
For the good of the community :)
[...]
Results:
Slashdot's editors are facists.
Launch conditions were 48,500 feet and 125 knots. All systems performed as expected and the vehicle landed successfully while demonstrating the maximum cross wind landing capability.
If it's for the good of the community, then don't put in your personal opinion in the middle of the post.
There may have been more random crap in there, this was the first one I saw. Feel free to remod the karma whore appropriately.
It is soooooo Buck Rogers-esque!! Not the late 70's/early 80's TV show Buck Rogers, I mean the 1930's - 1940's Buck Rogers.
We were somewhere around Barstow on the edge of the desert when the drugs began to take hold. - HST
Slashdot - the place where you can look like a genius by restating the obvious
Generally, bash is superior to python in those environments where python is not installed.
John Sauter (J_Sauter@Empire.Net)
It's about reaching 100KM, with at least 1 person, in a vehicle capable of carring 3, twice in 2 weeks.
Which is slightly more frequently than your average rural bus service.
Just wanted to point out that they're getting more than 2 hours of unpowered flight. That's pretty cool.
You quitting proves that the karma kap worked. The most annoying of the whores shut up. --CmdrTaco
The energy content of gasoline is about 42e6 J/kg.
Orbital velocity (at the surface of the earth) is about 8000 m/s. Kinetic energy of 1 kg at 8000 m/s is 32e6 J. (That is, you need about 32 MJ/kg)
However for those who want the whole story, the parent to this is correct: to get all that energy out of the kg of gasoline, you *also* need about 2.8 kg oxygen. Gasoline-oxygen gets you about 11 MJ/kg, which is about a third of what you need to hit orbital velocity.
To get to 100 km altitude, you need only 0.96 MJ/kg, which is no problem for gasoline-oxygen.
"There are a dozen opinions on a matter until you know the truth. Then there is only one." - CS Lewis (paraprhase)
I had given up on Scaled for a while after the landing gear issue- I checked faithfully every day, then every week hoping to get some news, afraid something had gone disastrously wrong.
My guess is they're going to do a flight or three with burn (with the new heatproofing) before the actual suborbital flight. Somebody ought to start a pool. $5.00 says they've 100km by July 4 :)
Any generalization is a stupid one.
IIRC, about the best available chemical combo is ClF5 / N2H4, which is absolutely horrendous in terms of handling, inflammability and toxicity.
T&K.
Political language
Nuclear reactions yield about a million times more energy per unit mass than do chemical reactions, so it's natural to try to get the energy that way.
NERVA got OK Isp (about a factor of 2 better than chemical rockets, something like 1000 seconds), but its thrust-to-weight ratio was pretty low, about 4 if I remember right. That's because it included a critical, operating nuclear reactor with an actively controlled chain reaction, and them thar things are heavy.
Thrust-to-weight is just as important as Isp to a rocket: higher thrust-to-weight means you can tote more fuel, payload, and structure for the same Isp, since you always have to have the mass of the engine itself around. By contrast to the NERVA's thrust-to-weight of about 4, the Space Shuttle main engines have a thrust-to-weight ratio of around 75. Since solid rockets are technically made out of their own fuel, their effective weight is much lower for this calculation (pretty much just the bell nozzle) and you might see numbers in the several-hundreds range.
Of course, one could always work on making the NERVA more lightweight -- but do you really want to optimize a nuclear reactor for mass, rather than safety? I didn't think so.
Now, for use in space, thrust-to-weight isn't so important. The rocket doesn't have to support itself against gravity, so low-mass engines that also produce low thrust are perfectly OK.
Of course, international treaty bans the use of critical nuclear reactors in space, but that alone wouldn't slow down our current administration very much.
[Nuclear reactors get flown into space all the time, but they always have much less than critical mass, relying on spontaneous decay to keep the chain reaction limping along at a constant rate. NERVA would require controlled reaction rates, hence a critical-mass reactor.]
The ship only has to have accomodations for three people. The rules allow for substituting ballast for the passenger's weight and letting the single pilot go up alone. The relevant rule is
This design also uses the wing itself as a massive air brake by tilting the wing, eliminating (or reducing) the need to assume a nose-high attitude (shuttle orbiters pitch up by 30-40 degrees for most of the re-entry phase of the mission, by comparison.)
i am a soviet space shuttle
The X-15 was relieved of having to rely on its own propulsion (for the most part) to reach that altitude. The aircraft was carried under the wing of a B-52, then dropped off at 45,000 feet after which the four hydrogen peroxide rocket motors would be ignited.
This one is to be flown by a single pilot, so it has a jet engine to make it faster, but they still expect it to take 3 days. I don't know how much auto pilot they expect to use, but it won't be nearly as much an achievement if they use it at all. That would almost turn it into nothing but a drone.
Infuriate left and right
How do you know how what sort of cooling mechanism is in place or how effective the heat shield will be? Just looking at pictures? For all you know there could be some elaborate fluid cooling system internally distributed, making blunt edges less necessary. Or that heat shield could be more effective than what your extensive calculations and research indicate.
My point is is that you shouldn't be so quick to judge. Or maybe you're just shoehorning some semi-related facts in an insightful-sounding post to raise your karma.
(btw I am an aeronautical engineering major)
A question: Is this design even intended as an orbital vehicle, or just a stepping stone (incidentally aimed at meeting X-prize requirements)? If it isn't intended to make it to orbital speeds, then there's no need to build in infrastructure that an orbital vehicle would need.
Another question (or two): What are the shallowest and steepest practical re-entry profile? If you could descend from orbit slowly enough, then you wouldn't need to decelerate at such a high rate that you would get the leading edge temperatures reached by the Shuttle. Then again, tearing through even the upper atmosphere at Mach 25 while trying to slowly burn off speed might cause too much heating. On the opposite end of the envelope, if one had sufficient retro-rocket capability, you could bleed off most of your orbital velocity while 100 km up, then freefall to an altitude where aerodynamic conditions are more friendly - but that would take a huge amount of fuel.
On the assumption that the Shuttle presents the state of the art in re-entry vehicles as it was 25 years ago, how have materials and fuels changed to push either end of the re-entry envelope (shallower vs. steeper)?
Less is more.
Yeah, NERVA demonstrated at least 900 seconds Isp if I remember right. The thrust-to-weight wasn't 4:1, but 3:4. In other words, it'd never be able to get itself off the ground.
Orion gets around the exhaust temperature problem by having the reaction external to the rocket. You've got a series of small nukes that create superheated plasma that pushes against a huge steel plate. 'Project Orion: The True Story of the Atomic Spaceship' by George Dyson goes into a lot of detail and presents some of the history behind the idea.
Shotgun!!!!!!
You know, now that I try to find the specs, it's not clear if it's 3:4, or '3 to 4'. Either way, it's not a lot. More recent designs have supposedly had ratios up to 27 or so, but I don't know if any have actually been built.
Who said anything about an RTG? Go look up Cosmos 954. It was one of several powered by a BES-5 reactor.
I don't have every answer, but here are a few facts:
...
You've got it right on the heat dissipation, though I mentioned that more to address comments that all the heat would be "taken" along the leading edges of the wings, which isn't the case even though they do tend to get pretty hot - which you can see in infrared pictures of the Shuttle as it descends.
This isn't an orbital vehicle, no. A flight will take around half an hour and it'll reach an altitude of 100km or so - across the official space boundary, but it won't stay there long. A lot more fuel would be required to reach orbital velocity, and a lot more heat shielding to make it back.
Re-entry profiles are usually "corridors" only a few degrees wide; come in too shallow, and you skip off the atmosphere; too steep, and you're crushed by G forces. The exact profile differs from design to design, I'd imagine.
Most of the envelope is determined by fuel and the shape of your ship. Amazing things can be done by designing your vehicle well and taking advantage of physics... take a look at the Sanger skip bomber", a suborbital craft designed to fly once around the world and make an unpowered glide landing, "skipping" off the atmosphere like a stone off water.
Notice how flat the underside of the spacecraft is
i am a soviet space shuttle
My mistake was in remembering subcritical multiplication being the dominant process when in fact it seems not to be for the RTG's we all know and love (the ones on Cassini).
You can check the cross sections and decay rates at the online chart of the nuclides, hosted in South Korea. (Until recently, that was hosted at BNL; does anyone else find it ironic that the Koreans are now exporting nuclear information to Berkeley?
I wouldn't trust any Thermal Protection System until all the employees have submitted their TPS reports in triplicate.
This account verified sig-free since..., uh, never mind.
Hmmm, no one apparently actually reads anymore..... A brief glance at the site makes it clear that Paul Allen is the financier.
If you don't believe me, look at the x-15 x-15 in full ablative coatings. The pilots wouldn't fly it unless they put a painted on top of it...
You forgot to include the potential energy required to get from earth's surface to orbit.
For LEO (200 km), circular orbit velocity is 7789 m/s. KE is 30.3 MJ. PE for 200 km altitude (from earth's surface to orbit) is 60.7 MJ. If you launch at the equator, prograde, then you gain 464 m/s, for an intial KE of 0.1 MJ.
So total energy required to transport 1 kg to 200 km LEO from stationary at earth's equator, is 90.9 MJ.
Of course, if you're burning the fuel along the way the energy requirement drops as mass decreases, and you also have to add in oxidizer mass, but I don't know the equations for that.
From what I've read, you can enter with almost any profile, as long as the vehicle is designed for it. The corridors are a function of the vehicle's limitations. Ballistic weapons enter using a ballistic profile, which has lower heating duration which is easily taken care of by ablative materials, but large G-forces. The capsules, Apollo and Soyuz, are close to ballistic, but generate some small lift, but again, it is mostly a short duration of heating and larger G-forces.
The Shuttle uses a low-G entry, requiring it to spend much more time exposed to the reentry heating, this is why ablative materials were not used.
This isn't quite correct. Here's a picture of SpaceShipOne feathered while descending. The fuselage is more or less parallel to the ground, with the wings and tail trailing above/behind to provide stability. I believe the wings are not used as an air brake but rather the fuselage is.
This makes sense because it allows for a wing design that is much lighter than it would otherwise have to be, and hence they can make the ship into a pretty good glider (unlike for example the space shuttle or X15) for the same take-off weight.
NERVA/KIWI was a cute run, but was messy as I recall.. About the only way at the time to get a NERVA vehicle into orbit was to perch it on top of a Saturn V and kick it off into orbit. With the premature termination of Apollo/Saturn, NERVA became a victim of circumstances.
Bring back the Saturn V and then we'll put NERVA back in business.
First rule of holes; When in one, stop digging.
Tell that to the bunch up in the Yukon that had a BES-5 drop on their heads from a failed apogee kick motor ignition.
Rutan isn't a brilliant designer. He is a brilliant marketer.
In the 70's, he wants to make a canard (a plane with the tail in the front) because he like the shape. He did the VariEze, wich is not a very bad plane but was far behind other classic designs of the times like the lancair or the glasair in terms of performance (with the same engine) or in terms of mass, wich lead to cost in aeronautics. This is due to the shape.
In the 80's, he did the world-around voyager. It's not an astounding piece of engineering, anyone could have done it, it's build light an fragile. It's more a piece of corones from the pilots (including his brother) who fly it: for example, it lost some parts on the takeoff, and they continue their trip however. It couldn't have been certified, and with a pretty big margin.
He also did another canard, the beech starship, a twin turboprop for eight people. It was canceled after one billion dollars of investment, and if it have been done, it would have been largely inferior to concurents like the piaggio avanti.
In the 90's, he done an assymetrical airplane, the boomerang. 500 million years of evolution tending to symetry doesn't bother him.
And now, the spaceshipone. honestly, i thought he can done it, even win the x prize. i hope. he's not stupid. but don't think he's a genius.
Hey slashdotters, doesn't this remind you of anything, someone who isn't very good at his stuff, but very smart in marketing, and is the leader?
--
Croco
Scaled Composites succeeds, refuels, and turns it in 24 hours. Or perhaps even same day...
I got $50 on Burt Rutan... As much as I respect Carmacks group, Rutan is the Man with his own private Skunkworks for decades, and does a lot of work for... Uh... Large Governments, with lots of guns.
According to wikipedia it was powered by an rtg. Now it's entirely possible that wikipedia is wrong, so if you can show me something credible that says otherwise I'll go change it...
They're the only ones with successful test flights already, right?
Where do you see 2+ hours?
Flight 49L / 12G
Date: 11 MAR 04 Flight Time: 1.3 hours / 18 mins 30 secs
Reads like 1.3 hours with White Knight to altitude, then 18:30 falling from 48000ft (seems about right for a flying brick, 2600 fpm).
The rocket engine has been tested on the ground at full power for an entire burn. The boost phase on the previous flight was stopped to keep the test program progressing in incremental stages. Binnie could have just as easily kept going well past 100 km, but they're still wringing out the subsystems. The rocket engine works. It's a very clever and simple system that uses nitrous oxide as the oxidizer and rubber as the fuel. The rocket can be throttled by changing the flow rate of the liquid oxidizer. A low cost, safe and throttleable solid rocket booster is quite an achievement (but not invented at Scaled).
To correct a couple of falacies in previous posts.... 100 km is the internationaly recognized limit for being an astronaut. Parabolic suborbital flights do not require heat shielding because they are much slower than orbital flights, not because they have less atmosphere to penetrate on reentry. Both are essentially in the vacuum of space.
I like the Armadillo Aerospace research too, but it isn't going to win the X-Prize. I think they should have called their rocket engine the BFR-9000.
And to the person who said the older Rutan aircraft designs are works of art, I'd have to agree. A picture of my Long-EZ is here.
The X-Prize is going to change the way we look at space. No longer will a $1B shuttle launch be required. We will all have access to space. This is long over due. My appreciation to those who are making it happen. As always, all that is required is big dreams, intelligence and determination.
>> My ultraviolent Linux switch video.
WTF does Rutan have to do with the gossamer planes? That was Paul McReady.
Wouldn't it be easier to reach orbital speeds once ur mostly out of the atmosphere?
You're 60.7 MJ/kg is actually for an altitude of ~200,000 km, not 200 km (gotta love those exponents!)
Incidentally, 91 MJ/kg will get you well past escape (escape potential is only 62.5 MJ/kg).
"There are a dozen opinions on a matter until you know the truth. Then there is only one." - CS Lewis (paraprhase)
XCOR has applied as well, though they are being even more coy than Scaled with what they are doing with their Xerus vehicle.
"Necessity is the plea for every infringement of human freedom. It is the argument of tyrants; it is the creed of slaves
Long ago I recall reading about a successor to NERVA, dubbed Dumbo (after the flying elephant). The limitations of NERVA were due to the design of the reactor (using reasonably standard fuel "pins" in a coolant/propellant) which gave it rather low limits for its rate of heat transfer and thus thrust. The idea of Dumbo was to redesign the fuel elements to be something like corrugated cardboard, with fissionable fuel in one half of the corrugations and open passages through the other halves. You'd have fuel elements composed of washers of some refractory, non-hydrogen-embrittling metal and Ruffles-style corrugated plates between them with the top half of the wavy plate full of fuel. The amount of surface area this would give you would be an order of magnitude or more above a standard design, so the potential heat transfer for a given delta-T would have more or less the same multiplier. Heat transfer translates directly to power level and to thrust. With modern machine welding, electrical-discharge machining and automated inspection I'll bet that such elements could be fabricated to a very high degree of isolation of fission products while keeping the performance near the theoretical limit.
More recently, DoD was talking about a heavy-lift hybrid nuclear rocket using a pebble-bed reactor design and anhydrous ammonia propellant (which might dissociate under the heat, lowering the MW of the exhaust from 17 toward 8.5 and further boosting the impulse). To allay the concerns of the environmentalists, it would have been boosted by a conventional first stage and only brought critical once it was high enough to expel things above the atmosphere. I don't recall the application, it might have been pop-up laser stations for ballistic missile defense.
We both know and can do a lot more now than we did then. If we really wanted to do it, we could do it. I have seen and walked around one of the NERVA nozzles, and I think it's a shame that such capability has never been put to use. The places we could have gone, the things we could have seen...
What the hell are we waiting for?
Time is Nature's way of keeping everything from happening at once... the bitch.