A new air speed record has been matched.
Yesterday, the USAF launched an experimental aircraft, the X-51A, and it achieved Mach 6 for more than 3 minutes. It used scram-jet technologies, a stepping stone towards space-planes.
Now there is still a long way to go. Mach 6 is fast, but three minuets is not very long and to reach orbital speeds you need something on the order of Mach 16 or 17. Still is is very cool that the USAF is still in the record busting business.
An interesting technical achievement, but…
The X-15 rocket plane flew just as fast (though perhaps not as far) in high speed atmospheric runs 50 years ago.
And air-breathing scramjets are extremely controversial in engineering circles as a means of cheaper access to space. The X-30 NASP, an example commonly used by scramjet critics, cited as a bottomless money pit that would never achieve it’s goal.
http://en.wikipedia.org/wiki/Rockwell_X-30