Detail View: NASA Image eXchange Collection: LDEF (Postflight), AO178 : A High-Resolution Study of Ultra-heavy Cosmic-Ray Nuclei, Tray A10

Title: 
LDEF (Postflight), AO178 : A High-Resolution Study of Ultra-heavy Cosmic-Ray Nuclei, Tray A10
Description: 
LDEF (Postflight), AO178 : A High-Resolution Study of Ultra-heavy Cosmic-Ray Nuclei, Tray A10 EL-1994-00122 LDEF (Postflight), AO178 : A High-Resolution Study of Ultra-heavy Cosmic-Ray Nuclei, Tray A10 The postflight photograph of the Ultra Heavy Cosmic Ray Experiment (UHCRE) was taken in the Orbiter Processing Facility (OPF) at KSC during removal of the LDEF from the Orbiters cargo bay. 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 upper 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 to have changed from specular to opaque (glossy white) with many black dots of various sizes that appear to be impact craters. An impact crater with a large area of discoloration is clearly visible in the upper right quadrant of the thermal cover. The dark discoloration is probably the results of an impact penetration of the 5 mil TEFLON® film allowing atomic oxygen to oxidize and erode the vapor deposited silver layer beneath. White dots of varying sizes can be seen on the cover, many appear to be encircling impact craters. The cover is not stretched as taut as in the flight photograph and locations of Velcro attach pads are not as prominent. The ground strap appears to be in place with no visible damage but appears to be a deeper copper color.
Date: 
01.30.1990
Credit: 
NASA Langley Research Center (NASA-LaRC) [ http://lisar.larc.nasa.gov/ ]
facet_what: 
Crater
facet_where: 
Langley Research Center (LaRC)
facet_when: 
01-30-1990
facet_when_year: 
1990
Media: 
IMAGE
ID: 
EL-1994-00122
UID: 
SPD-NIX-EL-1994-00122
original url: 
http://nix.ksc.nasa.gov/info?id=EL-1994-00122&orgid=1