SUPERSONIC JET TESTING

Fast track: Flight testing of a jet engine believed to be capable of propelling an airplane faster than any other aircraft powered by petroleum-based fuel has gotten the green light from the Pentagon.
Super supersonic: Researchers hope to fly five to eight unmanned X-51As at speeds up to seven times the speed of sound, or about 4,600 miles per hour. The flights are scheduled for December 2008 through January 2009 and are to be launched from Edwards Air Force Base in California.
Military muscle: The program is aimed at demonstrating practical technology for future military craft, including ultra-fast cruise missiles, global-range bombers and reusable satellite launchers.
Source: Associated Press