NASA Dryden Flight Research Center, Edwards, Calif., sent its fastest and highest-flying airplane, the SR-71A, into the air for further research flights to evaluate the SR-71's performance, handling and flying qualities with a test fixture mounted atop the aft section of the aircraft. This test fixture was originally used for the Linear Aerospike SR-71 Experiment (LASRE), supporting research for the X-33 program.
The flight of the SR-71 "A" model occurred on June 30, 1999, which was the first flight of this aircraft since October 29, 1998. The aircraft reached a maximum speed of Mach 2.25, about 1,450 mph at 55,000 feet. Three more flights are scheduled between July to September with the next flight planned for mid-July.
"The long anticipated prospect of getting the SR-71 aircraft back in the air is exhilarating," said Steve Schmidt, Dryden's SR-71 project manager. "This phase of the flight research program has gotten off to a great start in that the aircraft and project team performed flawlessly which is further testament of the cooperative "teamwork" that has been a sustaining hallmark of the SR-71 programs."
NASA's "B" model is used for proficiency training for pilots and the flight test engineers. Recently the "B" model completed its planned 200-hour phase inspection and has been put into flyable storage. These two SR-71s have been on loan to NASA from the U.S. Air Force, which just transferred ownership to NASA.
In addition to these two SR-71's, the Air Force turned over possession of its two other flyable SR-71s, which will complement the other two NASA planes in future flight research programs providing unsurpassed flexibility as well as additional capabilities to perform multiple high-speed research experiments.
The SR-71 can fly more than 2200 miles per hour, Mach3+ or three times the speed of sound, and at altitudes of over 85,000 feet. Data from the SR-71's high-speed research program will be used to aid designers of future supersonic and hypersonic aircraft and propulsion systems, including a high-speed civil transport. SR-71 flights have also provided information on the presence of atmospheric particles at extremely high altitudes, where future hypersonic aircraft will be operating.
As research platforms, the SR-71s carry out research and experiments in a variety of areas: aerodynamics, propulsion, structures, thermal protection materials, high-speed and high temperature instrumentation, atmospheric studies and sonic boom characteristics.
The LASRE project was a small, half-span model of a lifting body positioned on the rear of the SR-71 aircraft, which operated like an "airborne wind tunnel." The SR-71 has also acted as a surrogate satellite for transmitters and receivers on the ground, assisting in the development of a commercial satellite-based, instant and wireless, personal-communications network, called Iridium.
Another project with the SR-71 joined NASA and the University of California-Los Angeles (UCLA), investigating the use of charged chlorine atoms to protect and rebuild the ozone layer. Ongoing research in high-speed, high-altitude flight continues to gain interest among the scientific community, industry and other government agencies.