NASA TESTS INSULATION FOR SHUTTLE GOAL TO PREVENT DISASTER.

Byline: Jim Skeen Staff Writer

EDWARDS AIR FORCE BASE - Divots of insulation foam will be dropped from a specially-fitted F-15B fighter jet and photographed by high-speed cameras in research into making space shuttle flights safer.

Lending a hand in the efforts to return the space shuttle fleet to flight, NASA's Dryden Flight Research Center at Edwards is starting a test program costing about $2 million to see what happens to small pieces of foam debris that fall off the shuttle's external fuel tank after launch.

``We're glad to be able to do our part with this flight experiment,'' said Dryden Director Kevin Petersen. ``Every center is doing what it can for return to flight. This is a small piece of that puzzle.''

Falling insulation-foam debris led to the Feb. 1, 2003, accident that destroyed the shuttle Columbia and killed its seven-member crew. The foam damaged the shuttle's insulation, allowing the heat of re-entry to tear the spacecraft apart.

NASA officials will have the test data in hand in time for a decision on whether the planned launch of the orbiter Discovery in May or June can go forward.

NASA is also redesigning how the tank is attached to orbiters.

NASA scientists expect to prevent large chunks of foam from falling but doubt they can prevent small pieces from breaking off the tanks. As a shuttle ascends, changes in atmospheric pressure and increased heating cause foam pieces to separate from the tank.

Dryden's research is funded by NASA's Johnson Space Center.

To simulate foam coming off the external fuel tank, a test fixture with plates sprayed with foam will be mounted underneath Dryden's F-15B. The back of the foam will be pressurized with nitrogen, popping divots off the sheet, said project manager Stephen Corda.

Up to nine divots can pop off, one at a time, during a test. Diameter of the divots range in size from 2 inches to 7 inches, Corda said.

What happens to a divot after it is popped off the test fixture will be captured by two high-speed digital cameras, each capable of shooting 2,000 to 10,000 images per second.

``This will answer the question of if it stays intact or breaks up in a thousand pieces. If it stays intact, how will it orient itself and where does it go?'' Corda said. ``The first objective, to see if they break apart, will be self-evident when we look at the video.''

If the foam stays intact, the video cameras should help provide information to plot trajectories of foam debris.

The experiment will also help validate tools, such as high-speed video, for use in tracking debris during shuttle launches.

Jim Skeen, [phone]

james.skeen(at)dailynews.com