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AEDC assisted shuttle's return to flight

Wednesday, July 13, 2005

(Photo)
Computational fluid dynamics analysts Jim Greathouse and Darby Vicker and program manager Bob Ess, all from NASA's Johnson Space Center in Texas, examine a space shuttle model during a model change in the 16-foot transonic wind tunnel at the Air Force's Arnold Engineering Development Center. AEDC testing helped pave the way for the shuttle's return to flight today.
(AEDC file photo)
The U.S. Air Force's Arnold Engineering Development Center played an important role in supporting NASA's Space Shuttle Return to Flight program, leading up to today's planned launch of Space Shuttle Discovery.

U.S. Rep. Bart Gordon, the ranking member of the House Science Committee, planned to join other members of Congress to watch the launch at Kennedy Space Center in Florida.

"NASA and the Discovery crew have worked diligently to ensure that this flight will have an acceptable level of risk," said Gordon in a press release. "I wish the crew well on their mission."

"In just 2 1/2 years since the Columbia tragedy, NASA has made many changes to the shuttle in order to make flight safer," said Gordon.

Following the break up of Columbia during re-entry in February 2003, AEDC facilities and personnel experienced in manned space program testing responded to help NASA return to manned space flight. Return to Flight tests were conducted in five of AEDC's 58 testing facilities.

Here is a synopsis of the tests conducted at AEDC.

Wind tunnel testing

The first of three series of wind tunnel tests occurred in June 2003 in AEDC's Tunnel A. These tests demonstrated the aerodynamics of some of the Space Shuttle design changes and provided information on the aerodynamic heating caused by the new design during ascent.

Foam impact testing

Engineers and test operators in AEDC's S-3 Ballistic Impact Range launched hundreds of block-shaped projectiles made of the insulating foam material used on the shuttle's external tank. These "shots" simulated pieces of external tank foam breaking away from the tank during flight, as happened to Columbia, and striking various parts of the space shuttle such as the solid rocket booster.

Test operators launched the blocks at various velocities and angles to simulate the different ways in which foam might strike the boosters. These tests helped determine the effects of foam impact and provided information on the rocket booster's ability to withstand those impacts.

During each shot, high-pressure helium gas launched the foam projectiles at speeds from 150 to 2,255 feet per second down a 86-foot-long rectangular barrel.

High-speed video cameras operating at speeds up to 20,000 frames per second documented the impacts and provided a way of measuring the speed of the projectiles. Instruments acquired data at 50,000 samples per second to provide information on the stresses the targets sustained during the impact.

"Full stack" testing

AEDC completed a week of testing on a 3-percent scale "full stack" model in the center's 16-foot transonic wind tunnel in October 2004. The "full stack" model represents a space shuttle configuration similar to the vehicle at launch, with the external fuel tanks attached.

The people of AEDC are proud of the important role they played in returning the shuttle to flight.

AEDC has a long history of supporting the nation's manned space programs. AEDC played a key role in the development of projects Mercury, Gemini and Apollo. The center also provided critical testing to the development of the space shuttle.

The nation's largest complex of flight simulation test facilities, AEDC was dedicated in June 1951 by President Harry Truman and named after 5-star General of the Air Force Henry 'Hap' Arnold, visionary leader of the Army Air Forces in World War II and the only airman to hold 5-star rank. Today, this $7.8 billion complex has 58 aerospace test facilities located at Arnold Air Force Base, Tenn., and the center's remote operating location Hypervelocity Tunnel 9 in White Oak, Md. The test facilities simulate flight from subsonic to hypersonic speeds at altitudes from sea level to space. Every high performance flight system in use by the Department of Defense today and all NASA manned spacecraft have been tested in AEDC's facilities.