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To: Red Badger

No, the SCRAMJET must be brought up to operating speed with jet engines or rockets. This one is supposed to be able to take off from the ground, although I believe it would be more efficient for it to be dropped from a cargo jet.


26 posted on 11/29/2012 12:38:17 PM PST by Blood of Tyrants (Why is the government more concerned about protecting a microbe on Mars than an unborn baby here?)
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To: Blood of Tyrants; Red Badger

At least one earlier SSTO concept (from the US) called for a craft that would take off like a plane, carrying fuel, but breathing atmospheric oxygen; as it gained sufficient velocity, it would use its variable geometry inlet to turn its engine into a ramjet; as velocity continue to rise, the engine would become a scramjet; eventually this would result in an altitude beyond which insufficient oxygen is available, even at the high velocity, and cryo oxygen carried aboard the craft would first supplement, then replace the outside oxygen, making it a straight-up rocket engine.

The problem with the concept was and is, weight savings from not carrying oxygen would be at least partly offset by the added weight of the shifty engines. And again, the vehicle would have a small payload.

Here’s a fun idea from NASA — a sort of iterative concept growing out of Gerald Bull’s early 1960s experiments of firing “Martlets” out of extended gun barrels into suborbital trajectories at least 70 miles high. Too bad he tried to build his Supergun for Saddam, didn’t quite live through that one.

http://www.popsci.com/technology/article/2010-11/nasa-engineers-propose-combining-rail-gun-and-scramjet-fire-spacecraft-orbit


32 posted on 11/30/2012 7:00:33 PM PST by SunkenCiv (https://secure.freerepublic.com/donate/)
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