AIR AND SPACE  JULY 2004

NASA is using an aging fleet of research aircraft-including retired B-57 bombers, a T-38 jet trainer, and the venerable UH-l helicopter-to help get the space shuttle safely off the ground. A team at Johnson Space Center in Houston and Marshall Space Flight Center in Huntsville , Alabama , is developing a package of imaging sensors to potentially track the shuttle from liftoff to solid rocket booster separation-2.5 minutes into the flight ­to detect any debris that might damage the vehicle during launch. (NASA is also adding cameras to the external tank, the solid rocket boosters, and the orbiter.)

"The film camera failed during the Columbia launch, and the backup was just a regular video camera, but the resolution on it was not good enough to see much," says Rodney Grubbs, program manager for the WB-57 Ascent Video Experiment.  "Nobody could say with any confidence what, if anything, had struck the shuttle during liftoff"

WAVE will place pods of sensors on a pair of NASA's WE-57s.  "The WE-57 is sort of like a U-2 on steroids," says Andrew Roberts, WE-57 program manager.  "We can fly to a very high altitude and stay there." The former bomber will zoom up to about 65,000 feet.  "We'll fly both WE-57s about 14 miles away from the shuttle and have the pods trained on both sides of the shuttle during liftoff," Roberts says.  The WAVE sensors include a high-definition television camera, a wide field-of-view camera, and an infrared camera.  "The infrared gives us the ability to see another part of the spectrum so that we can detect it in the visible," says Grubbs. "If something falls off the shuttle and can't be seen or doesn't reflect visible light, then perhaps we can detect the heat or 'see' it in the infrared."

In developing WAVE, NASA turned to the Army for help.  The Army uses a "Fat Boy" pod, built by Southern Research Institute, to test missile sensors that its contractors supply.  NASA filled the gimballed Fat Boy pod with imaging devices, and in February engineers ran tests at Marshall, with a UH-l helicopter standing in for a WE-57 and a T-38 mimicking the shuttle at liftoff.  The T -38 flew by the UH-l, which carried Fat Boy on its side, at 330 mph and 500 feet off the ground.  "We calculated the speed and trajectory of the T-38 and where the helicopter was going to have to be to approximate flight conditions of a shuttle," says Grubbs. "We flew the helicopter at 2,000 feet and slightly less than two miles away from the target, the T -38." The pilot then pulled the trainer into a 45-degree climb to mimic a shuttle liftoff. The results of the test flights are under study. "The Air Force is going to help us with the contract with Southern Research Institute to actually build the gimbal if we get approval [to produce WAVE]," Grubbs says.

-Shelby G. Spires

PHOTO CAPTION

The Martin B-57 was used early in the Vietnam War and for high-altitude reconnaissance missions over Russia and China. NASA has used WB-57s, primarily for atmospheric research, since the late 1960s; now it is enlisting its fleet in a test program to capture images of the space shuttle as it launches. The goal: spot any debris that could damage the vehicle.

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