LDEF (Flight), S0109 : Fiber Optic Data Transmission Experiment, Tray C12

The Fiber Optic Data Transmission Experiment (FODTE) flight photograph was taken while the LDEF was attached to the Orbiter's RMS arm prior to berthing in the Orbiter's cargo bay. The white paint dots on clamp blocks at each end of the experiment tray lower flange appear to be discolored. The FODTE occupies a six (6) inch deep LDEF peripheral tray and consist of an aluminum internal support structure, four aluminum mounting plates, an aluminum cover plate, ten fiber optic cable samples with connectors, aluminum brackets and non-magnet fasteners required to assemble the experiment. Four optical fiber cables (two black, one blue and one bright orange), each configured in the form of a planar, helix coil, are attached to the thermally isolated mounting plates with black anodized aluminum clips cushioned with silicone-rubber spacers. The four mounting plates are coated with a Catalac off-white thermal control paint and the exposed surface of the cover plate is painted with Chemglaze II A-276 white to meet thermal control requirements. Six additional coils of optical fiber cable samples, secured with nylon cable ties, are located in the bottom of the tray, four below the mounting plates and two below the cover plate. Each sample terminates in connectors mounted in brackets located in the tray bottom or on the backside of the thermally isolated mounting plates. The FODTE appears to be intact with no apparent physical damage. A flow pattern of discoloration appears to the right of each fastener used to secure the four mounting plates. Colors of two of the four exposed coils of fiber optic cables have changed significantly. The cable located in the upper right corner, originally a bright orange, appears to be dark blue and the cable in the lower left position has faded from a light blue to a blue-gray color. The color of the silicone-rubber spacers under the coil attach clips appears to have changed from clear to brown. Two brown circular discolorations have appeared, one on the lower edge of the mounting plate in the upper left location and one on the upper edge of the mounting plate in the lower right position. Dark brown irregular shaped discolorations can also be seen along the lower edge and on each of the vertical edges of the cover plate.
NASA Identifier: L90-10501 S32-89-048