LDEF (Flight), S0001 : Space Debris Impact Experiment, Tray D06

The flight/on-orbit photograph of the D06 integrated tray was taken from the Orbiter aft flight deck during the LDEF retrieval, while the spacecraft was attached to the remote manipulator system. During the mission, the tray surface was at an angle of approximately eighty-two (82) degrees to the orbital velocity vector and therefore exposed to a higher atomic oxygen flux than if it had been parallel with the velocity vector. Note the difference in color of the paint dots on tray clampblocks; white dots along the top edge, a light tan color on the center dot and a dark brown stain on the dots along the bottom of the photograph. The dots near the top of the photograph are adjacent to experiment location D07 and are exposed to a higher atomic oxygen flux than those adjacent to experiment location D05. Impacts of atomic oxygen with a surface tends to scrub away contamination from the that surface and leave it a much cleaner. The two (2) Space Debris Impact Experiment detector plates, located in the center and left end sections of a three (3) inch deep experiment tray, show fingerprints and a palm print that occurred during installation of the panelsDE:into the tray. These prints are not visible on the prelaunch photograph. The light angle is such that the panel serial numbers, stamped in the upper left corner of the each panel, can be seen. The grazing light angle also makes numerous impact craters visible that would not be easily detectible if the light source was perpendicular to the tray surface. When comparing the flightDE:photograph with the prelaunch photograph, A switch in panel colors can be seen. The flight tray has a center section panel with a green tint and an end section panel with a pink tint. The opposite is seen in the prelaunch tray photograph. The center section panel has the pink tint and the end section panel is pale green. No definitive answer has been determined for the visual changes.
NASA Identifier: L90-10455 S32-82-009