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Second Hypersonic X43 Scramjet Ready for Testing
Dan writes "I am sure most of you remember how NASA was forced destroy their first hypersonic X43 seconds in it's maiden flight, which was a big setback for the american hypersonic scramjet program. Well NASA just finished one of the final tests and is preparing to launch it as early as February 21! I wish them the best."
Happy Trails,
Erick
http://www.busyweather.com/
This is great technology, but remember, it's not for *us*, it's for the military. Faster jets, bigger killing radius, when will this benefit freedom and peace?
"Who are in control, they are not in control of anything - they don't even control themselves!" - Glen Beck
I don't know for you, but I find manned high speed flights (X1, X15) much more exciting to witness from a human perspective than those remote-controlled ones. I realize the objective is to test an engine and that there's no need to put a human being in danger to achieve that anymore, but it doesn't produce heroic stories and certainly doesn't make children dream like it used to.
I find the old crappy 1969 b/w pictures of the first man on the moon much more appealing than the Spirit panoramas, yet the probe went much further than Armstrong, and probably did a lot more science. But still, it's not the same thing, and NASA should send actually people up-diddly-up instead of drones, just because (1) there would be volunteers and (2) they would strike the public's imagination and generate sympathy for that kind of research, which in turn would turn into funding...
"A door is what a dog is perpetually on the wrong side of" - Ogden Nash
For the several earlier posters who seem to think that this is the Holy Grail of Earth-to-orbit transportation -- well, maybe they're right in that it's about equally unattainable. Rockets work a hell of a lot better - as has been demonstrated by almost 47 years of orbital flight.
Any airbreathing technology suffers a couple of fundamental flaws when it comes to suborbital, let alone orbital, transport. Most obvious, the air is mighty thin up there -- so you've got to stay where the air is thicker to support combustion. (Which basically means you can't make orbit with out at least some kind of apogee kick rocket).
Secondly, pushing through all that air creates drag. Now, you either aggravate the problem by slowing the relative airspeed enough to support combustion -- meaning increasing the drag on that air (supersonic combustion alleviates this somewhat), or you don't slow it down (relatively, actually you're speeding the air up), have a harder time maintaining combustion, and more significantly, have a much lower momentum delta in the exhaust -- meaning less push to the vehicle.
Scramjets have some limited use for high speed short range flight but rockets are far more efficient and the only practical way to get to orbit.
(And while I may not be a rocket scientist, I've had long talks about just this with some very expert rocket scientists, such as Max Hunter.)
-- Alastair
this will be THE means to get to a station in Earth orbit, and from there, nuclear rockets out into the farther reaches of the solar system. I'd love to see colonies on Mars as much as the next geek, but until we get it through our heads that we need to have stepping stones along the way, we aren't going to be successful. It is simply too damn expensive to develop an entirely new system for every "space objective". We need a new way into Earth orbit... and a space station whose primary objective is to be a way station where deep space nuclear propulsion systems can launch for the rest of the solar system without contaminating the environment here on earth. Maybe someday materials science will make possible the space elevator (and it may be closer than I think, but until they're spinning line, I'm not counting on it....) but until then, we need a different solution beyond out brute force approach. This could be the technology that opens up just these sorts of possibilities.
Scramjets combust the air at supersonic velocities rather than diffusing it prior to combustion the way most other engines in supersonic vehicles do. There's a lot of promise here. But in a society that can't make the Concorde profitable, will it be worth it in the end? I'd love to be able to fly to the other side of the world in something less than 24 hours. The economics of the situation seem to be against us, though.
"You can never have too many elephants on your team."
The liquid fueled rockets that nasa uses today use liquid hydrogen and liquid oxygen in the reaction:
2 H2 + O2 -> 2 H2O
Which means that by mass modern rockets use about 8 times as much oxygen as they use hydrogen.
At cruise in the Concorde, you could apparently feel heat from the windows due to the air friction. The SR-71's fuselage stretched over a foot at high speed. So if you're going faster again, you're going to need some pretty impressive materials to keep the fuselage together. I'm guessing metal's probably not up to it. Maybe some sort of woven carbon fibre like on the stealth bomber?
One of these days I'm moving to Theory - everything works there
The XB-70 Valkyrie flew at mach 3.1. But it's thermal protection consisted of stainless steel and thin white paint. The only figures I can find on the internet say the SR-71 toped out at mach 3.2. It seems odd that the SR-71 required so much more thermal protection when it's top speed was less than 100 mph faster.
It's used to dangle the expensive Pegasus conventional rocket that the X-43 uses for its first stage.
I wonder: when did "literally" start gliding from "is exactly" to "is very much like" in some people's mind?