NASA to Attempt Mach 10 Flight Next Week

Dirak writes "NASA intends to break its own aircraft-speed record for the second time this year by flying X43a scramjet ten times faster than sound. On November 15 the X-43A supersonic-combustion ramjet - or scramjet - will again take to the skies aiming for Mach 10."

What is the Speed of Sound?

[Anonymous Coward]

Just above the atmosphere, what is the speed of sound? I guess when an article says 10 times the speed of sound it means the speed of sound at sea level right? But this aircraft isn't at sea level. This aircraft skips on top of the atmosphere pulsing the scramjets while dropping into the atmosphere.

The speed of sound isn't a good tool to measure the speed, as the speed of sound without an atmosphere is either infinite, undefined, zero or a combination of the choices. I mean once you get into space, should you add the speed the earth is rotating plus the speed around the sun using a basis of sound?

Aurora?

[NetNinja]

And the Aurora aircraft will be the chase planes correct :)

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The B-52

[OverlordQ]

The B-52, the American workhorse for over 50 years. So called 'Weapons of War' can be used for other, good purposes, like this.

Re:Practical application

[trybywrench]

I'm all for fast cool stuff, and technical gadgetry, but anyone know of any practical uses for this? I mean, wouldn't it run into the same sonic boom issues as the concorde? Perhaps even worse?

This would make an incredibly formidable cruise missile. You could launch it basically from anywhere in the world and it would arrive on target within a couple of hours. No near-deployment required.. you could launch it from your backyard in Nebraska. I'm all for peace, smiles and sunshine but the military uses for this are incredible.

Re:Fast times at tax-payers' expense

[pi_rules]

do you know how much health care or education $125 Million will purchase?

Yeah, a couple of Band-aid's and a pencil or two for every citizen.

You could build, maybe, 8 schools with that kinda cash.

Woooooo!

This is what NASA is meant FOR

[Thud457]

People, people. This is what NASA should be doing. Basic aeronautical research.

Then some smartass hillbilly with nine-inch sideburns can make use of their research to build a rocketplane and proclaim : "Spaceship 2, Government 0"!

Rockets vs. Jet Engines

[hey!]

Yes, but the shuttle is launched by rockets, not jet engines.

I am not an aeronautical engineer or even much of a space buff by /. standards, but my understanding of the situation is that rockets carry both fuel and oxygen, whereas jets carry just fuel and breathe oxygen from the atmosphere. What I think this means is that to the degree you can get the speed you need to access space using a jet in the atmosphere, you can dispense with carrying some of the oxygen.

Again, in my naive, non expert way, I look at a typical rocket and see a huge cylinder of fuel and oxidant with a teeny tiny payload on top. Even a marginal reduction in the size of the non-payload part has got to make a big difference in cost per pound of payload. I'm guessing this is leading to systems in which the first stage to orbit consists of a reusable scramjet powered vehicle that takes the next stage above the atmosphere.

Re:What are the Vegas Odds of this working?

[IdahoEv]

I don't think it will. I just doubt the plane will hold together with that much pressure on it

Why not? The Space Shuttle goes more than twice that fast during reentry into the atmosphere, and held together under "that much pressure" more that a hundred consecutive times. It only failed last time because of gross damage to the leading edge of a wing.

You don't think NASA's engineers are smart enough to calculate the pressure at mach 10 and build accordingly?

I wouldn't be too stunned if the flight fails (since it is a new technology), but I doubt it will be from the hull being to weak to withstand the forces placed on it at speed.

Re:is it REALLY an "Aircraft"?

[Control Group]

Yes. A rocket is entirely self-contained: its fuel and reaction mass are both stored internally (and are generally the same thing, in point of fact)*. The scramjet carries its fuel onboard, but the reaction mass is the atmosphere.

*Actually, it's possible that the term "rocket" specifically means that the fuel and the reaction mass are the same thing, but I'm not certain of that, since I've seen terms like "nuclear rocket" used quite often (though perhaps incorrectly), and those do decouple fuel and reaction mass.

Re:Poor budget managment.

[HokieJP]

Your understanding is not correct.

NASA and the Air Force were going to co-operate on the X43-C project (a follow on to the X43-A), but it was cancelled. However, hypersonics research at NASA is not over. You can read all about it here [aviationnow.com].

One reason why it makes sense for NASA to work on this is that the technology may be used to improve access to space. This is not an avenue the USAF is likely to pursue.

Aviation Technology Week's take on Scramjet

[DumbSwede]

On the downside I read a recent Aviation Technology Week that states that the Mach 10 flight is the end of current funding for Hypersonic Flight research. Evidently there are not concrete plans to keep going even if this flight is a success, though it seems unlikely NASA would let the program die completely (like other X projects).

Also stated in the ATW was that there wasn't (or shouldn't) be any animosity between the Scramjet team and the Rocket technology teams, in that affordable scramjet is projected to top out in the 20,000 lbs to LEO range and have a $1,700 per pound price tag vs $2,200 for expendable rocket, but with rocket being able to heft much larger loads. Still, the 20,000 lbs range is projected to meet 80% of future lift needs.

This figures struck me has oddly pessimistic, but they see problems scaling with this technology. They think the real advantage to scramjet will be reliability, with current unmanned failures rates (and manned it would seem also) at one in 50, and scramjet figured at 1 in 4000 or so (assuming a return to Earth on propulsion failure). Of course the Shuttle was projected to have a low failure rate also.

Still I would think a four-tier approach would be near ideal for now.
Maglev assist takeoff to Mach 1 or 2
Jet assist to Mach 3 or 4 (stubby winged, high-speed, jet wouldn't have enough lift for loaded takeoff on it's own)
Scramjet to Mach 8 or 10
Rocket final stage to Mach 22 orbit.

Maybe Congress doesn't want to fund this because they're misreading Scramjet as Scam-Jet.

I've heard similar stories.

[i41Overlord]

I've read plenty of stories from Blackbird pilots on usenet, and it sounds like getting a lock on a Blackbird is not hard at all. You can track satellites by radar, too, but you'll have a hell of a time trying to shoot one down. The problem is getting your missile to reach it. By the time you get a lock and the missile is fired, the Blackbird has already put quite some distance on you. You need to remember that it flies at 80-100,000 feet in altitude, so the missile will have to climb about 30-40,000 feet vertical just to be at the same level. Also, most air-air missiles have a top speed of Mach 3-4. Basically the missile won't catch up to it very fast, and it will run out of fuel before it ever does. I think the common stat that I've heard is that the Blackbird was fired at over 3,000 times, but was never hit.

Re:What is the Speed of Sound?

[caswelmo]

If there's no sound, there's no oxygen. If there's no oxygen, there's no boom. If there's no boom, there's no vroom. It's an air-breather.