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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."
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?
Now they can hurtle spacecraft towards Mars even faster before they malfunction and drift into outer space :D
All this extra speed will not be available for the common public until they can resolve the problem with the sonic boom. Once that is resolved I think it would be a lot more interesting where they could have supersonic flights that go over land as well. And the general public will advance. Right now having an airplain that can go at Mach 10 is somewhat useless because we can already out fly our enemies planes which most were build during the cold war times.
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Ludicrous Speed!
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?
Or is this just a method for getting something to go fast enough to put it into orbit without a rocket? (which would be quite useful)
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The B-52, the American workhorse for over 50 years. So called 'Weapons of War' can be used for other, good purposes, like this.
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I'm tired of hearing people yap about tax money when they waste money on frivolous things. Not to say that video games are bad, but do you know how much health care or education $125 Million will purchase? And the general public dropped that in one day! Do you know how much good research $125 M will purchase? I haven't looked it up, but I'm guessing the X-43A project is on the same order of magnitude cost-wise as what the public spent on this one single video game.
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I'm sure this aircraft will create a lot of wind when it goes by. This wind can then be harnessed by windmills, which will produce electricity. The electricity can be used for electrolysis, producing hydrogen. The hydrogen can be converted into jet fuel. It's the perfect cycle!
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If successful it would be a great accomplishment. However, according to this Wired article, 00.html?tw=wn_tophead_3,
http://www.wired.com/news/technology/0,1282,65671
NASA is "phasing out its hypersonic engine program to free up funding for President Bush's 'Vision for Space Exploration,' which calls on NASA to focus its energy on sending humans to the moon and Mars."
Therefore,
"As of now, next week's X-43A flight is the final flight in the $230 million program."
I can't help but wonder if these priorities are correct as I'm not quite sure what we intend to do after we reach the moon and Mars.
I think that if the theoretical parameters of the ideal scramjet play out in practice, they'll be a very efficient motor for getting things into low earth orbit.
Sure, they don't work outside the atmosphere, but what about a next-gen shuttle that develops most of its thrust during the scramjet phase, uses a small rocket motor to get that extra bit of velocity at the upper end, and still has enough room left over for some worthwhile payload?
I imagine that's the kind of thing NASA's interested in.
Space Ship Two, anyone?
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The U.S. Blackbird spy plane was _really_ fast when it came out. It is still probably one of the fastest aircrafts out there. Maybe still the fastest.
The Swedish fighter jet, Viggen (which is built by SAAB) was the first fighter plane to ever get a "lock" on the blackbird.
The Swedish radar systems got it on radar. The Viggen flew to intercept it with after burners on the whole time.
It got a lock on it and then had to turn back because it was out of fuel. There was of course never any intention of firing a missile, but still.
The black bird crew sent a box of chocolate to the Swedish air base and said "Congratulations!".
At least, this is what I heard. Whether it really is true, I couldn't tell you for sure.
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Then some smartass hillbilly with nine-inch sideburns can make use of their research to build a rocketplane and proclaim : "Spaceship 2, Government 0"!
the preceding comment is my own and in no way reflects the opinion of the Joint Chiefs of Staff
Yes, but the shuttle is launched by rockets, not jet engines.
/. 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.
I am not an aeronautical engineer or even much of a space buff by
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.
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It will be 10 times the speed of sound at the altitude the craft will be flying.
t ml
You can't take the sea level speed of mach and multiply it by 10, because that would be incorrect. The speed of sound is about 760 mph at sea level, while at 95,000 feet (where the HyperX flies), the speed of sound is about 677 mph.
So when it flies Mach 10 it is not going 7,600 mph, it is going 6770 mph.
This is a common mistake that I see being made. Same thing with the SR-71...it is often quoted by dumb journalists as going 2280 mph, which is Mach 3 at speed level. But it can't go Mach 3 at speed level, it would break apart. It goes Mach 3 at 85,000 feet, which is about 1992 mph.
There's a cool utility for calculating Mach here: http://www.grc.nasa.gov/WWW/K-12/airplane/sound.h
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.
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Did everybody wake up and take a stupid pill this morning or something? The arguments about this being too fast for commercial flight are in the same vein as early arguments that noboby would ever need more than 64KB of memory. Of course this is acceptable speed for commercial flights. It'll take a while to get there, but it will happen
The speed of sound in a gas is related to the temperature of the gas and the gas properties molecular weight and heat capacity (cp/cv).
The relationship is:
c = sqrt(j * R * T / M)
where:
c = speed of sound
j = ratio of heat capacity (cp/cv)
R = Universal gas constant
T = Temperature (for gases always use absolute temperature)
M = Molecular weight
The Mach number is the ratio of the speed of an object over the speed of sound of the medium that the object is moving trough.
The X-43A will be released at 40,000 ft and climb to 110,000. I am not very sure about the temperature at this altitude but I think is about -100 C or 173K. At that temperature speed of sound is:
264 m/sec
So Mach 10 would be:
2640 m/sec or 5900 mph
If X-43 could fly that fast lets say at, 1000 ft, mach 10 would be about 3400 m/s or 7600 mph. Unfortunately the air density at 1000 ft would not allow X-43 to go that fast.