scholarly journals Lessons Learned from Atomic Oxygen Interaction with Spacecraft Materials in Low Earth Orbit

2009 ◽  
Author(s):  
Bruce A. Banks ◽  
Kim K. de Groh ◽  
Sharon K. Miller ◽  
Deborah L. Waters ◽  
Jacob I. Kleiman
Keyword(s):  
Atomic Oxygen ◽  
Low Earth Orbit ◽  
Lessons Learned ◽  
Earth Orbit ◽  
Oxygen Interaction

Monte Carlo Modeling of Atomic Oxygen Interaction with Protected Polymers for Projection of Materials Durability in Low Earth Orbit

1992 ◽  
Vol 278 ◽  
Author(s):  
Bruce A. Banks ◽  
Bruce M. Auer ◽  
Sharon K. Rutledge ◽  
Linda Gebauer ◽  
Edward A. Sechkar
Keyword(s):  
Monte Carlo ◽  
Atomic Oxygen ◽  
Protective Coatings ◽  
Polymeric Materials ◽  
Low Earth Orbit ◽  
Earth Orbit ◽  
Textured Surfaces ◽  
Photovoltaic Array ◽  
Defect Sites ◽  
Oxygen Interaction

AbstractAtomic oxygen in low Earth orbit (LEO) readily attacks and oxidizes exposed spacecraft polymeric materials such as polyimide Kapton photovoltaic array blankets. The application of thin film silicon dioxide protective coatings can greatly extend the useful life of such materials in LEO. A Monte Carlo computational model has been developed which simulates atomic oxygen interaction with polymeric and protective coating materials for both ground laboratory and in-space experiments, allowing the determination of the geometrical shape of atomic oxygen attack of protected polymeric materials at defect sites in protective coatings. Modeling of attack of unprotected carbon-carbon composite materials predicts textured surfaces suitable for high emittance radiators. Results for fiberglass composites indicate loss of the matrix polymer leading to friable fibers. The computational modeling to project in-space performance based on ground laboratory testing predicts mass loss per fluence in space to be approximately one third that observed in plasma ashers.

scholarly journals The Effect of Low Earth Orbit Atomic Oxygen Exposure on Phenylphosphine Oxide-Containing Polymers

2000 ◽  
Vol 12 (1) ◽  
pp. 43-52 ◽  
Author(s):  
John W Connell
Keyword(s):  
Thin Film ◽  
Atomic Oxygen ◽  
Low Earth Orbit ◽  
Space Environment ◽  
Earth Orbit ◽  
Cooperative Effort ◽  
Flight Experiment ◽  
Oxygen Exposure ◽  
Atomic Oxygen Exposure ◽  
Phenylphosphine Oxide

Thin films of phenylphosphine oxide-containing polymers were exposed to low Earth orbit aboard a space shuttle flight (STS-85) as part of flight experiment designated Evaluation of Space Environment and Effects on Materials (ESEM). This flight experiment was a cooperative effort between the NASA Langley Research Center (LaRC) and the National Space Development Agency of Japan (NASDA). The thin-film samples described herein were part of an atomic oxygen exposure (AOE) experiment and were exposed to primarily atomic oxygen (∼1×1019 atoms cm−2). The thin-film samples consisted of three phosphine oxide-containing polymers (arylene ether, benzimidazole and imide). Based on post-flight analyses using atomic force microscopy, x-ray photo-electron spectroscopy and weight loss data, it was found that the exposure of these materials to atomic oxygen (AO) produces a phosphorus oxide layer on the surface of the samples. Earlier work has shown that this layer provides a barrier towards further attack by AO. Consequently, these materials do not exhibit linear erosion rates which is in contrast with most organic polymers. Qualitatively, the results obtained from these analyses compare favourably with those obtained from samples exposed to AO and/or an oxygen plasma in ground-based exposure experiments. The results of the low Earth orbit AO exposure on these materials will be compared with those of ground-based exposure to AO.

Concentration of atomic oxygen in low earth orbit and in the laboratory for use in high quality oxide thin film growth

1998 ◽  
Author(s):  
J. A. Schultz ◽  
K. Eipers-Smith ◽  
K. Waters ◽  
S. Schultz ◽  
M. Sterling ◽  
...  
Keyword(s):  
Thin Film ◽  
Atomic Oxygen ◽  
Film Growth ◽  
Low Earth Orbit ◽  
Thin Film Growth ◽  
Oxide Thin Film ◽  
Earth Orbit ◽  
High Quality

Atomic Oxygen Plasma Effects on Cvd Deposited Diamond-Like Carbon Films

1991 ◽  
Vol 236 ◽  
Author(s):  
Jeffrey S. Hale ◽  
R.A. Synowicki ◽  
S. Nafis ◽  
John A. Woollam
Keyword(s):  
Atomic Oxygen ◽  
Moisture Absorption ◽  
Crystalline Silicon ◽  
Carbon Films ◽  
Fused Silica ◽  
Low Earth Orbit ◽  
Index Of Refraction ◽  
Earth Orbit ◽  
Diamond Like Carbon ◽  
Space Flights

AbstractCVD deposited diamond-like carbon (DLC) films have been studied for possible use as a secondary standard for Low Earth Orbit materials degradation. Samples of various thicknesses have been exposed to a simulated Low Earth Orbit atomic oxygen (AO) environment using a plasma asher. Mass loss measurements indicate that DLC degrades at a rate of 0.7 mg/hr which is two to three times the rate of currently used Kapton samples which degrade at a rate of.3 mg/hr. Thickness measurements show that DLC thins at a rate of 77 Angstroms/min. Since DLC is not as susceptible to environmental factors such as moisture absorption, it could potentially provide more accurate measurements of AO fluence on short space flights. Adhesion of DLC films to both fused silica and crystalline silicon substrates has been studied under thermal cycling conditions. Film adhesion to fused silica can be enhanced by sputtering a thin layer of silicon dioxide onto the substrate prior to deposition. In addition to the above, the index of refraction and extinction coefficient of various thicknesses of DLC films has been characterized by Variable Angle Spectroscopic Ellipsometry.

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