LEO degradation of graphite and carbon-based composites aboard Space Shuttle Flight STS-46
- Union Carbide Corp., Parma, OH (United States)
Six different types of carbon and carbon-boron nitride composites were exposed to low Earth orbit aboard Space Shuttle flight STS-46. The samples received a nominal atomic oxygen fluence of 2.2 x 10(exp 20) atoms/sq cm in 42 hours of exposure. Pyrolytic graphite and highly oriented pyrolytic graphite showed significant degradation, and the measured erosion yield was within a factor of two of published values. The erosion yield of pyrolytic boron nitride was found to be 2.6 x 10(exp 26) cu cm/atom in plasma asher exposure, over 42 times lower than that of pyrolytic graphite. This low erosion yield makes graphite plus boron nitride mixtures quite resistant to low Earth orbit exposure. Evidence suggests that the graphitic component was preferentially etched, leaving the surface boron nitride rich. Degradation resistance increases with boron nitride composition. Carbon fiber/carbon composites degraded in low Earth orbit, and the carbon pitch binder was found to etch more easily than the graphite fibers which have much higher degradation resistance.
- Research Organization:
- NASA Langley Research Center, Hampton, VA (United States)
- OSTI ID:
- 79518
- Report Number(s):
- N-95-27629; NASA-CP-3275-PT-3; L-17430C-PT-3; NAS-1.55:3275-PT-3; CONF-9311137-; CNN: NAG3-95; TRN: 9527636
- Resource Relation:
- Conference: 3. long duration exposure flight (LDEF) symposium, Williamsburg, VA (United States), 8-12 Nov 1993; Other Information: PBD: Feb 1995; Related Information: Is Part Of LDEF: 69 Months in Space. Third Post-Retrieval Symposium, part 3; Levine, A.S.; PB: [10] p.
- Country of Publication:
- United States
- Language:
- English
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