LDEF (Postflight), AO178 : A High-Resolution Study of Ultra-heavy Cosmic-Ray Nuclei, Tray D07

LDEF (Postflight), AO178 : A High-Resolution Study of Ultra-heavy Cosmic-Ray Nuclei, Tray D07 EL-1994-00207 LDEF (Postflight), AO178 : A High-Resolution Study of Ultra-heavy Cosmic-Ray Nuclei, Tray D07 The postflight photograph of the Ultra Heavy Cosmic Ray Experiment (UHCRE) was taken in SAEF II at KSC after removal of the experiment tray from the LDEF. The experiment tray flanges appear to be discolored by a light brown stain. An outline of experiment tray clamp block locations is clearly visible on the experiment trays upper flange and to a lesser extent on its lower flange. The holding fixture hardware covers the clamp block areas on the end flanges. The UHCRE detectors were contained in 16 peripheral LDEF trays with at least one UHCRE tray located on each row of the LDEF except row 3, row 9 and row 12. Each tray contains three cylindrical aluminum pressure vessels with an integral aluminum support structure. Each cylinder is filled with an Eccofoam insert that houses 4 UHCRE detector stacks. Each stack consist of layers of Lexan polycarbonate sheets (approximately 70) interleaved with several thin sheets of lead. Forty-seven of the 48 pressure vessels were pressurized to 1.0 bar of a dry gas mixture (oxygen, nitrogen and helium) and sealed. One of the units was left unsealed in order to investigate the effects of the vacuum environment on the detector materials. Thermal control was accomplished by attaching an aluminized Kapton thermal cover on the tray bottom (the Kapton facing the LDEF interior), placing the aluminum cylinder support structure on thermal isolators and covering the experiment with a thin (5 mil) silvered TEFLON_ thermal cover. The silvered TEFLON_ cover was supported by an aluminum frame, an integral part of the experiment structure, and held in place by Velcro pads selectively located on the frame and on the back of the cover. The copper colored strip extending over the trays lower flange is a copper coated pressure sensitive tape used to provide an electrical ground between the experiments thermal cover and the LDEF structure. The UHCRE thermal covers surface appears specular with green and white discolorations associated with photo lights and reflections of the surrounding area. The black and/or brown dots of various sizes appear to be points of impact and penetration of the TEFLON_ cover. The impact point discoloration is probably the results of a penetration in the 5 mil TEFLON_ film that affected the vapor deposited silver and inconel layers beneath.. The cover is not as taut as in the flight photograph and locations of the Velcro attach pads are not as prominent. The ground strap appears to be intact with no visible damage but appears to be a darker copper color than in the prelaunch photograph.
NASA Identifier: NIX-EL-1994-00207