NASA's hypersonic X-43A scramjet, short for supersonic combustion ramjet, makes a historic test flight this week.
The X-43A will fly seven times the speed of sound, using air-breathing scramjet engines instead of traditional rocket power.
Scramjet propulsion technology will revolutionize present rockets motors by scooping oxygen from the atmosphere at high altitudes,
instead of carrying oxygen in tanks, saving weight and onboard space.
Attached to a modified Pegasus booster, the X-43A will be air-launched from under NASA's B-52 aircraft carrier at 40,000 feet altitude.
The Pegasus booster will accelerate the experimental vehicle to Mach 7 at about 95,000 feet altitude.
At booster burnout, the X-43A will separate and fly under its own power, on a preprogrammed path, over the Pacific ocean.
The X-43 is considered hypersonic, the term for flight at or above five times the speed of sound
and could represent a major leap forward in the goal of providing faster, more reliable and less expensive access to space.