Scramjet Engine : X-43A

NASA's unmanned X-43A test craft reached the speed of 8,000 Kmph on Saturday before it took a deep dive into the Pacific Ocean as it was planned. The vehicle was dropped from a B-52. 12-foot-long wingless X-43A was used to test an ultra-high-speed engine called a scramjet which the researchers are working on as hypersonic speed engine for a long time.

The project manager for the X-43A said that every bit of the experiment was successful. The experimental scramjet -- supersonic combustion ramjet -- is being tested in a nearly $230 million program to develop technology for possible use in future space launch vehicles and for high-speed military and civilian aircraft. Beauty of a scramjet engine is that it pulls oxygen for combustion from the atmosphere rather than carry the extra weight of its own oxygen as a rocket does. This helps the engine in carrying extra equipments which was not possible by the engines (rockets) carrying load of fuel.

The first attempt at flying an X-43, in June 2001 had ended with destroying the craft by the controllers intentionally when the Pegasus booster rocket carrying it went out of control after the rocket's control fins broke off in order to prevent any disaster. Several factors were blamed for the 2001 malfunction, one of them the launching of the booster rocket-mounted X-43 at 23,000-foot altitude, where the atmosphere is much denser than the 40,000-foot level at which Pegasus rockets are launched when they go into space. The booster's fin actuator system was beefed up for Saturday's test, and the rocket was to be let go at 40,000 feet.

The NASA B-52 flew carrying the booster-mounted X-43A from Edwards Air Force Base over the Naval Air Warfare Center Weapons Division Sea Range off the central California coast. The bomber released at 40,000 feet, on release from the converted bomber, the Pegasus booster rocket fired, propelling the X-43 to an altitude of 95,000 feet and a speed of Mach 7, roughly 4,900 mph. As the booster engine burned out, the X-43 separated and fired its scramjet engine for about 10 seconds. Then it performed a set of preprogrammed maneuvers before crashing into the ocean. Although the scramjet runs just seconds, the test's data is hoped to validate wind-tunnel tests and other ground research, NASA officials said.

Plans call for flying one other X-43A vehicle, which will hit a top speed of about 7,000 mph. The X-43 was destroyed after the experimental flight. The X-43 is NASA's first test program dedicated to hypersonic research since the last X-15 rocket plane flight at Edwards Air Force Base in 1968. The X-15's fastest flight was Mach 6.7, or about 4,520 mph.