A NASA McDONNELL Douglas F-15 has been used to prove the durability of materials for the thermal-protection system (TPS) proposed for the X-33 re-usable launch vehicle.

NASA says that the tests of the TPS were vital because of the threat posed to protective materials by rain drops, cloud droplets or ice crystals during ascent and landing. "The proposed requirement of 'launch on demand' for the X-33 requires that TPS materials resist damage from these high-velocity impacts," says NASA.

The TPS test tiles are made from ceramic and metallic materials designed by NASA and Rockwell. Twelve tiles were mounted at various angles on a test fixture which was placed on the centreline stores pylon of NASA's F-15B flight-test fixture (FTF-II) testbed aircraft. The aircraft was also fitted with a particle-measurement probe and video cameras to record close-up damage to tiles as it occurred.

The tests, at Edwards AFB, California, are a virtual re-enactment of similar trials undertaken in September 1985 in which NASA's Lockheed F-104 was used to test Space Shuttle tiles. The F-15B uses the same particle-measurement probe as that used on the F-104.

Source: Flight International