Abstract
Second surface silver microsheet glass concentrators are being developed for potential use in future solar dynamic space power systems. Traditional concentrators are aluminum honeycomb sandwich composites with either aluminum or graphite epoxy face sheets, where a reflective aluminum layer is deposited onto an organic leveling layer on the face sheet. To protect the underlying layers, a SiO2 layer is applied on top of the aluminum reflective layer. These concentrators may be vulnerable to atomic oxygen degradation due to possible atomic oxygen attack of the organic layers at defect sites in the protective and reflective coatings. A second surface microsheet glass concentrator would be inherently more atomic oxygen durable than these first surface concentrators. In addition, a second surface microsheet glass concentrator design provides a smooth optical surface and allows for silver to be used as a reflective layer, which would improve the reflectivity of the concentrator and the performance of the system. A potential threat to the performance of second surface microsheet glass concentrators is atomic oxygen attack of the underlying silver at seams and edges or at micrometeoroid and debris (MMD) impacts sites. Second surface silver microsheet glass concentrator samples were fabricated and tested for atomic oxygen durability. The samples were iteratively exposed to an atomic oxygen environment in a plasma asher. Samples were evaluated for potential degradation at fabrication seams, simulated MMD impact sites, and edges. Optical microscopy was used to evaluate atomic oxygen degradation. Reflectance was obtained for an impacted sample prior to and after atomic oxygen exposure. After an initial atomic oxygen exposure to an effective fluence of ≈1×1021 atoms/cm2, oxidation of the silver at defect sites and edges was observed. Exposure to an additional ≈1×1021 atoms/cm2 caused no observed increase in oxidation. Oxidation at an impact site caused negligible changes in reflectance. In all cases oxidation was found to be confined to the vicinity of the seams, impact sites, edges or defect sites. Asher to in-space atomic oxygen correlation issues will be addressed.
This is a preview of subscription content, log in via an institution.
Buying options
Tax calculation will be finalised at checkout
Purchases are for personal use only
Learn about institutional subscriptionsPreview
Unable to display preview. Download preview PDF.
References
Staff of Solar Dynamic Power System Branch, “Solar Dynamic Power System Development for Space Station Freedom,” NASA RP 1310, July 1993.
Bahnman, D. W. and Jensen, P. A., “Design of a Solar Concentrator for the Solar Dynamic Ground Test Demonstration Program,” Solar Engineering 1994, presented at the 1994 ASME/JSME/JSES International Solar Energy Conference, San Francisco, CA, March 27–30, 1994, pp. 193–203.
Jaworske, D. A., de Groh, K. K., Podojil, G. M., McCollum, T. A. and J. Anzic, “Leveling Coatings for Reducing Atomic Oxygen Defect Density in Graphite Fiber-Epoxy Composites,” J. of the IES, May-June 1994, pp. 26–31.
de Groh, K. K., Dever, T. M. and Quinn, W. F., “The Effect of Leveling Coatings on the Atomic Oxygen Durability of Solar Concentrator Surfaces,” NASA TM-102557, 1990.
Rutledge, S. K. and Olle, R. M., “Space Station Freedom Solar Array Blanket Coverlay Atomic Oxygen Durability Testing Results,” 38th International SAMPE Symposium, May 10–13, 1993, pp. 679–693.
de Groh, K. K., Dever, J. A., McCollum, T. A., Rodriguez, E., Burke, C. and Terlep J. A., “Low Earth Orbit Durability Evaluation of Solar Concentrator Materials,” Solar Engineering 1992, Vol.2, presented at the 1992 ASME/JSME/JSES International Solar Energy Conference, Maui, HI, April 5–9, 1992, pp. 775–782.
Rutledge, S. K. and Mihelcic, J. A., “Undercutting of Defects in Thin Film Protective Coatings on Polymer Surfaces Exposed to Atomic Oxygen,” NASA TM-101986, 1989.
de Groh, K. K. and Banks, B. A., “Atomic-Oxygen Undercutting of Long Duration Exposure Facility Aluminized-Kapton Multilayer Insulation,” Journal of Spacecraft and Rockets, Vol. 31, No. 4, July–August 1994, pp. 656–664.
de Groh, K. K. and Banks, B. A., “Low Earth Orbit Atomic Oxygen Simulation for Durability Evaluation of Solar Reflector Surfaces,” 17th Space Simulation Conference Terrestrial Test for Space Success, NASA CP 3131, 1992, pp. 1–17.
Richter, S. W. and Lacy, D. E., “Overview of the NASA Lewis Advanced Microsheet Glass Concentrator Program,” 1990, pp. 361–366.
Solar Engineering 1990, presented at the 12th Annual ASME International Solar Energy Conference, Miami, Fl, April 1–4, 1990, pp. 775–782.
de Groh, K. K., Banks, B.A. and Smith D. C., “Environmental Durability Issues for Solar Dynamic Power Systems in Low Earth Orbit,” Solar Engineering 1995, Vol.2, presented at the 1995 ASME/JSME/JSES International Solar Energy Conference, Maui, HI, March 19–24, 1995, pp. 939–949, also NASA TM-106775.
Koontz, S. L., Albyn K. and Leger, L. J., “Atomic Oxygen Testing with Thermal Atom Systems: A Critical Evaluation,” Journal of Spacecraft and Rockets, Vol. 28, No. 3, May–June, 1991, pp. 315–323.
Banks, B. A., Rutledge, S. K., de Groh, K. K., Stidham, C. R., Gebauer, L. and LaMoreaux, C. M., “Atomic Oxygen Durability Evaluation of Protected Polymers Using Thermal Energy Plasma Systems,” NASA TM-106855, 1993.
Banks, B. A., Auer, B. M. Rutledge, S. K., de Groh, K. K. and Gebauer, L., “The Use of Plasma Ashers and Monte Carlo Modeling for the Projection of Atomic Oxygen Durability of Protected Polymers in Low Earth Orbit,” 17th Space Simulation Conference Terrestrial Test for Space Success, NASA CP-3131, 1992, pp. 37–48.
de Groh, K. K. and McCollum, T. A., “Low Earth Orbit Durability of Protected Silicone for Refractive Photovoltaic Concentrator Arrays”, Journal of Spacecraft and Rockets, Vol 32, No. 1, January–February 1995, pp. 103–109.
Author information
Authors and Affiliations
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 1999 Springer Science+Business Media Dordrecht
About this paper
Cite this paper
de Groh, K.K., Jaworske, D.A., Smith, D.C., Mroz, T.S. (1999). Atomic Oxygen Durability of Second Surface Silver Microsheet Glass Concentrators. In: Kleiman, J.I., Tennyson, R.C. (eds) Protection of Materials and Structures from the Low Earth Orbit Space Environment. Space Technology Proceedings, vol 2. Springer, Dordrecht. https://doi.org/10.1007/978-94-011-4768-2_4
Download citation
DOI: https://doi.org/10.1007/978-94-011-4768-2_4
Publisher Name: Springer, Dordrecht
Print ISBN: 978-94-010-6004-2
Online ISBN: 978-94-011-4768-2
eBook Packages: Springer Book Archive