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View Full Version : X-43A successfully tests scramjet

BigJim
2004-Mar-28, 03:44 AM
NASA successfully flew an X-43A today (http://www.space.com/missionlaunches/x43_launch_040327.html), marking the first flight of a scramjet in history. =D>

Tensor
2004-Mar-28, 04:03 AM
Cool, thanks for the post and link Jim. I've been looking for it since it was announced the test would be Saturday.

The Watcher
2004-Mar-28, 04:19 AM
How Fast??
5000 mph!!
Wow.

One thought occurs. If it goes that fast wouldn't it just achieve escape velocity and ignore the curve of the earth and go in a straight line through the atmosphere?.
Of course there will be no air for fuel but what about momentum? They cannot rely on less fuel to keep it from shooting out of the atmosphere can they? Or am I missing something?

Granted this was only a test flight but if in the future it keeps a constant 5000mph would it have to steer downwards a little to keep it's altitude?

Hey, my 50th post. WooHoo!

2004-Mar-28, 04:36 AM
One thought occurs. If it goes that fast wouldn't it just achieve escape velocity and ignore the curve of the earth and go in a straight line through the atmosphere?.
Of course there will be no air for fuel but what about momentum? They cannot rely on less fuel to keep it from shooting out of the atmosphere can they? Or am I missing something?

Granted this was only a test flight but if in the future it keeps a constant 5000mph would it have to steer downwards a little to keep it's altitude?

5,000 mph is very fast, but not fast enough to either reach orbit or escape from earth. Orbit velocity is 7.9 km/s and escape velocity is 11.2 km/s. In mph, the orbital velocity would is 18,000 mph. This is not fast enough to stay in orbit, let alone escape from the Earth altogether.

2004-Mar-28, 05:20 AM
Yeah was kinda neat. Was flipping through the channels in the afternoon and one of the local 24 hr news stations carried the feed of the test. Lots of waiting for the test to happen and when it did...WOW!!!! (mind you all that one could see was the contrail up to the separation of the booster). Guess they'll be going over the data from this test for quite some time. They know the technology works, up to the goal they set for the test, now comes the fun of seeing how far they can go with it.

Quartermain
2004-Mar-28, 08:29 AM
Very exciting news! I followed the lead up to the first test in 2001 launch, which sadly ended in the manual-destruction of the test vehicle. So I'm very excited to see a successful flight second time around. I hope the results are favorable to leap into full scale scram jet testing.

Glom
2004-Mar-28, 12:42 PM
That's cool.

constible
2004-Mar-28, 01:59 PM

It was suppose to start at 3pm EST and I spent two hours watching it on NASA tv through realplayer. There was a lot of boring stuff beforehand, but the end was well worth it.

tracer
2004-Mar-28, 05:00 PM
5,000 mph is very fast, but not fast enough to either reach orbit or escape from earth. Orbit velocity is 7.9 km/s and escape velocity is 11.2 km/s.
For those of you playing along at home, 5000 mph is 2.235 km/s. (Unless you're talking about nautical miles per hour, in which case it's 2.572 km/s.)

skrap1r0n
2004-Mar-28, 09:07 PM
Isn't escape velocity in the neighborhood of Mach 20?

2004-Mar-28, 09:16 PM
Isn't escape velocity in the neighborhood of Mach 20?
If you define the speed of sound as 1 atmospheric pressure, escape velocity is actually more than Mach 20, i think.

Diamond
2004-Mar-29, 07:55 AM
I think you'l find that escape velocity refers to impulse flight, not continuous burn.

daver
2004-Mar-29, 06:30 PM
Isn't escape velocity in the neighborhood of Mach 20?
If you define the speed of sound as 1 atmospheric pressure, escape velocity is actually more than Mach 20, i think.
Escape velocity is around mach 34, orbital velocity around mach 24.

mach numbers here are pretty meaningless.

Wingnut Ninja
2004-Mar-29, 09:33 PM
It was suppose to start at 3pm EST and I spent two hours watching it on NASA tv through realplayer. There was a lot of boring stuff beforehand, but the end was well worth it.

I would have watched just on the off chance it might crash/explode/do something involving large fireballs. It's like NASCAR times a hundred.