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."

Lucky 13?

[dont_call_me_jim]

So does that mean that SpaceShipOne will be making a run for the money soon?

missing flights?

[Anonymous Coward]

so what happened to flights 9 through 11? The flight log jumps from flight 8 (first powered) to this latest one.

Armadillo Aerospace

[Sparky77]

I've been following the X-Prize work at Armadillo [armadilloaerospace.com] 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.

Re:Minimal info

[ferralis]

He's probably doing the same thing I am- hitting their site periodically for an update.

Needed: Improved Fuels

[stuffduff]

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!

Re:Minimal info

[SeaDour]

To say they're "being very quiet about this" is an understatement. They didn't even announce the project until well after it had gone through the design and prototype phases. Additionally, the test flights have usually been announced and discussed at least a week after their occurance. Also, we're still not even sure who all the investors in the project are. I would guess that the main reason they're keeping it so secretive is to prevent other teams from gaining the upperhand.

Re:heat shielding

[RichMan]

This is a sub-orbital flight. A parabolic up-down with "comparativly little" speed WRT the ground. A true orbital flight needs momentum to balance out gravity. This means a lot higher ground speed for an orbital flight.

As this is not an orbital flight there is no excessive velocity to burn off. Hence, the bathtub mode of recovery from altitude.

Re:Armadillo Dreamin'

[Skyshadow]

I'm not sure it's fair to characterize Rutan and Carmack this way.

Neither of these guys are professional rocket builders. They're both private individuals spending their (ample) money to compete for the X-prize. Rutan has previous experience building aircraft and has worked more at putting together a team and securing infrastructure to help with the build, but it's not as if Rutan is leading a billion-dollar team of button-down 1950's engineers at Boeing or something while Carmack is competing out of his back yard shed.

Just because Carmack posts his day-to-day struggles on the web for us all to enjoy (and I *do* enjoy it, BTW) doesn't imply that the SpaceShipOne team isn't encountering the exact same sorts of technical hurdles, supply problems, permit bullshit and etc. In other words, whichever wins will be a victory for the little guy because they're *both* the little guy.

Re:Needed: Improved Fuels

[onkelonkel]

Give yer head a shake, lad. 2 or 3 orders of magnitude means 100 to 1000 times more (unspecified rocket fuel goodness).
Improvements usually come a few percent at a time.

Re:Cute text changes

[TwistedGreen]

Either some moderators were sleeping, or else they agree with the assertion.

It's probably a bit of both, if you ask me.

Re:Minimal info

[Ed_Moyse]

i doubt microsoft has a whole lot to do with it, i think its just probably him trying to get some fame by getting them into space.

Or maybe he's just unbelievably rich, thinks that this is a cool project and wants to support it? Lets go easy on the cynicism folks!

Re:Looks good

[Orne]

I wouldn't get too down. This is the USA after all, and the race is rarely won by the "first", and usually won by the "cost efficient" (or, if you're a cynic, it's won by the "heavily marketed").

After all, today's commercial airline industry [airlinetechnology.net] isn't flying planes built by Burgess, Curtiss, or Loening [centennialofflight.gov]... It was Boeing who got the contracts for training planes during World War I, and commercial transport planes afterwards...

Re:Minimal info

[Buran]

On the other hand, civilian access to space finally becoming a reality is an incredible thing. It gives me hope, as a nearly lifelong enthusiast, that I may see space firsthand before I die, not via Celestis. This should be laid bare for the public, but it is not... we only find out about any progress weeks or months later when I'd rather the info go up within hours, which is certainly possible these days.

There is no longer any need to keep secret the fact that people and objects can get to space - Wernher von Braun wanted to try it way back in 1945, but his A-9/A-10 project got killed and it took him almost 20 more years before he accomplished that goal. If there was ever any time for secrecy, it was way back then when all this was still a surprise to spring on the bad guys. Not when there's about to be a change as big as the one we went through when Gagarin and Shepard went up.

The why (and some of the difficulties) of NERVA

[Dr. Zowie]

Yup, chemical rockets can't get much past about 500 seconds because there just isn't any more energy in chemical bonds. The game in rocketry is to dump as much momentum as possible into as little propellant as possible. The rub: putting momentum into mass requires energy. Momentum scales linearly with your rocket's exhaust speed; but the kinetic energy of the exhaust scales like the square of the exhaust speed! Hence, the more propellant efficient you are, the more energy you need per unit mass. If I recall right, the most energetic-per-unit-mass reaction is atomic hydrogen bonding with atomic fluorine, yielding 0.1 eV/amu of fuel -- that translates to 9.6 megajoules per kg of fuel, or (with perfect conversion) about 4500 meters/second exhaust speed. Divide by 10 m/sec^2 to get Isp, and you find that 450 seconds is the limit for chemical rockets.

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.]

Re:Armadillo Aerospace

[AKAImBatman]

If you asked me a month ago, I would have said Rutan has it. With all the understanding I've gained of rockets in the past month or so, I'd say its a toss up. Each design presents its own design challenges. Rutan can make test flights because of his decision to use a winged craft. OTOH, Carmack is already getting far more power out of his engines. We'll see which one takes the cake.

Re:Lucky 13?

[rijrunner]

The thing to keep in mind about Scaled and some of the other groups out there is that they are working on building suborbital vehicles as a goal in, and of, itself.

Which means that the X-Prize is incidental to Scaled goals here. Scaled is getting paid on contract terms to build this vehicle and it's pretty clear that the prize is just an incidental side-issue to their planned goal. The backers had this in line a long time before X-Prize was fully funded and they did not even enter it until after the Prize was fully funded.

Their primary goal is basically an extension of the tourist market like commercial flights in former military jets. There is a market for people paying $65k to go supersonic. This is something that is their primary goal. An incidental prize of $10 million is not something that can be counted on, so it really won't make much difference to a number of X-Prize developers. They are aiming for a specific niche market that can recover their costs regardless of whether they win the prize, or not.

They are going onto the next phase of flights. That's about all that can be said for it. There isn't much leeway in terms of timing now. If it isn't a go, they aren't going to rush things. $10 million is a lot less than what has been invested in it to this point and their primary aim is to recover the whole amount and then some. The best way to do that is systematically test and improve the vehicle. Their flight rate is remaining consistant to basic flight test timelines. Somewhere in Scaled, there will be a timeline with all sorts of milestones. It could on track for a flight within the prize window. Or not. Either way, they'll fly it when they have tested it to those parameters.

no pilot will fly a pink spaceship...

[black_widow]

If you don't believe me, look at the x-15 x-15 in full ablative coatings [nasa.gov]. The pilots wouldn't fly it [nasa.gov] unless they put a painted on top of it...

SS1 At 100 km This Year

[Long-EZ]

Burt Rutan and the Scaled Composites team will win the X-Prize. They are a lot closer than many /. pundits seem to believe. A lot of rocket test programs are scary because there can be no progressive testing. Test some subsystems, then put them together and "light the candle". The Scaled approach is more like an airplane test program, with a gradually expanding envelope. There is still work to be done, but they are very close.

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 [thinkingdevices.com].

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.