Tutorial: Atomic Oxygen Effects and Contamination
Sharon Miller
NASA Glenn Research Center
Sharon Miller is a Senior Research Engineer with NASA Glenn Research Center. She graduated from Case Western Reserve University with a Masters degree in Materials Science and Engineering and from Cleveland State University with a Bachelors Degree in Chemical Engineering. During her 36 years at NASA, she has conducted research in the areas of thin film coatings, surface texturing processes, atomic oxygen interactions, space environment effects and spin-off applications of these technologies. She has authored and co-authored over 120 technical publications and has seven patents.
Abstract
Atomic oxygen is the most predominant specie in low Earth orbit (LEO) and is contained in the upper atmosphere of many other planetary bodies. Formed by photo-dissociation of molecular oxygen, it is highly reactive and... [ view full abstract ]
Atomic oxygen is the most predominant specie in low Earth orbit (LEO) and is contained in the upper atmosphere of many other planetary bodies. Formed by photo-dissociation of molecular oxygen, it is highly reactive and energetic enough to break chemical bonds on the surface of many materials and react with them to form either stable or volatile oxides. The extent of the damage for spacecraft depends a lot on how much atomic oxygen arrives at the surface, the energy of the atoms, and the reactivity of the material that is exposed to it. Oxide formation can result in shrinkage, cracking, or erosion which can also result in changes in optical, thermal, or mechanical properties of the materials exposed. The extent of the reaction can be affected by mechanical loading, temperature, and other environmental components such as ultraviolet radiation or charged particles. Atomic oxygen generally causes a surface reaction, but it can scatter under coatings and into crevices causing oxidation much farther into a spacecraft surface or structure than would be expected.
Contamination can also affect system performance. Contamination is generally caused by arrival of volatile species that condense on spacecraft surfaces. The volatiles are typically a result of outgassing of materials that are on the spacecraft. Once the volatiles are condensed on a surface, they can then be fixed on the surface by ultraviolet radiation and/or atomic oxygen reaction to form stable surface contaminants that can change optical and thermal properties of materials in power systems, thermal systems, and sensors.
This tutorial discusses atomic oxygen erosion and contaminate formation, and the effect they have on typical spacecraft materials. Scattering of atomic oxygen, some effects of combined environments and examples of effects of atomic oxygen and contamination on spacecraft systems and components will also be presented.
Authors
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Sharon Miller
(NASA Glenn Research Center)
Topic Areas
Testing / Mitigation , Ionosphere, Neutral Atmosphere, Planetary , Atmospheric Effects (e.g., drag, AO, sputtering, glow)
Session
T1 » Tutorial: Atomic Oxygen Effects and Contamination (13:00 - Monday, 15th May)
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