NASA's X-43A Proves Hypersonic Scramjet Flight

[Chen]

http://www.sciencedaily.com/releases/2004/03/040329074842.htm

Sounds pretty neat, but I'm wondering what NASA is going to do with an oxygen-based scramjet engine. Here (http://www.thedailyfarce.com/science.cfm?story=2004%5C03%5Cscience_x43aflies7ti messpeedofsound_03200400054) it says "If we can get up to 10 times the speed of sound, man, we could probably get another $10 Billion from President Bush. He loves fast machines. I'll probably tell him that we can use the X-43A to go to the Moon or Mars. He'll love that." But how can this engine be used to go the Moon if there is no air along the way?!

(It took a lot of inner strength to ignore the humor in the quote by the way... I'd like to keep this on topic. :wink:)

[LURCH]

The engine that took the Appollo missions to the moon did not burn most of the way there. These missions were accomplished by one big push at the beginning, then a lot of coasting. Most of the fuel burned on these missions was burned getting off the ground and up out of the atmosphere, while accelerating up to orbital speeds.The X-34 (well, actually, one of its larger decendants) can get this job done far more cheaply. After Mach 10 is achieved and the craft has left the atmosphere, rocket engines can do the rest.

With very little rocket boost, the hypersoar could be a spaceshuttle, or with even less rocket power (launched from a payload bay), it could be a very cheap method for delivering sattelites into orbit. Of course, this latter technique can also be used to put components for a Moon launch, or even a Mars launch into orbit, which is a much cheaper start-point from which to launch these missions.

[Chen]

Ok, I understood that much. But how will they take off from Mars or the Moon with these engines? There is no air over there, is there?

[enigma]

No,

A rocket of some sort will be needed in that case.

The scramjets aren't going to be enough on their own to get to orbit, but they can still provide the majority of the velocity. Every kg of oxidizer you pull from the air instead of bringing it along for the ride is more mass you can get to orbit.

More feasable offshoots of the research will be ultra-high fast shipments (when it absolutely, positively, has to be there yesterday...) or weapon systems (why use stealth when you're going so fast they can barely see you, let alone hit you).

[Ivan Seeking]

ultra-high fast shipments (when it absolutely, positively, has to be there yesterday...)

:biggrin:

I have been hearing promises of the day that I can fly to China for lunch for most of my life; not that I could ever afford it mind you. This is the first real indicator that I have seen that such a thing might happen anytime soon - say in the next 20 or 30 years.

I predict that space elevators will eventually make this all a moot point for getting to space. It seems to me that the economy of elevators must win out once the technology becomes possible...which some claim is now.

Anyway, this is really, really cool. It's about time. :smile:

[russ_watters]

Anyway, this is really, really cool. It's about time. :smile: My thoughts exactly. I remember reading about this stuff like 15 years ago.