Atomic oxygen durability of solar-concentrator materials for Space Station Freedom
The findings are reviewed of atomic oxygen exposure testing of candidate solar concentrator materials containing SiO2 and Al2O3 protective coatings for use on Space Station Freedom solar dynamic power modules. Both continuous and iterative atomic oxygen exposure tests were conducted. Iterative air plasma ashing resulted in larger specular reflectance decreases and solar absorptance increases than continuous ashing to the same fluence, and appears to provide a more severe environment than the continuous atomic oxygen exposure that would occur in the low Earth orbit environment. First generation concentrator fabrication techniques produced surface defects including scratches, macroscopic bumps, dendritic regions, porosity, haziness, and pin hole defects. Several of these defects appear to be preferential sites for atomic oxygen attack leading to erosive undercutting. Extensive undercutting and flaking of reflective and protective coatings were found to be promoted through an undercutting tearing propagation process. Atomic oxygen erosion processes and effects on optical performance is presented.
- Research Organization:
- National Aeronautics and Space Administration, Cleveland, OH (United States). Lewis Research Center
- OSTI ID:
- 5352811
- Report Number(s):
- N-92-20065; NASA-TM-105378; E-6745; NAS-1.15:105378; CONF-9009307-; CNN: NCC3-19
- Resource Relation:
- Conference: Air Force workshop on surface reactions in the space environment, Evanston, IL (United States), 24-25 Sep 1990; Other Information: Sponsored by Northwestern Univ
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
36 MATERIALS SCIENCE
ALUMINIUM OXIDES
EROSION
PROTECTIVE COATINGS
PERFORMANCE TESTING
SILICON OXIDES
SOLAR CONCENTRATORS
SPACE VEHICLES
ATOMIC BEAMS
DEFECTS
FABRICATION
OPTICAL PROPERTIES
OXYGEN
POROSITY
SPECTRAL REFLECTANCE
ALUMINIUM COMPOUNDS
BEAMS
CHALCOGENIDES
COATINGS
ELEMENTS
EQUIPMENT
NONMETALS
OXIDES
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
SILICON COMPOUNDS
SOLAR EQUIPMENT
TESTING
VEHICLES
141000* - Solar Collectors & Concentrators
360205 - Ceramics
Cermets
& Refractories- Corrosion & Erosion