The Industrial Physicist has a detailed review of last years successful test of a scramjet.
Their description of “what is a scramjet” still left me wondering “what is a scramjet??” but basically its a conventional jet engine on steroids, where air at supersonic speeds is mixed with jet fuel and combusted. End result: very fast engine, reusable, much cheaper than the space shuttle.
In the NASA test last year the scramjet worked for 10 seconds and zoomed to a speed of Mach 7, or 5,000mph.
I know, you can’t get far in 10 seconds, but the conclusion of the article is that this test proved the scramjet theories and that we should have scramjet missiles in 5 years, scramjet planes in 10 years, and scramjet spacecraft in 15 years.
Personally I can’t wait for it to take 3 hrs to fly to Australia instead of 24hrs.