scholarly journals Effect of simultaneous N2 collisions on atomic oxygen-induced polyimide erosion in sub-low Earth orbit: comparison of laboratory and SLATS data

2021 ◽  
Author(s):  
Kumiko Yokota ◽  
Masahito Tagawa ◽  
Yusuke Fujimoto ◽  
Wataru Ide ◽  
Yugo Kimoto ◽  
...  
Keyword(s):  
Atomic Oxygen ◽  
Collision Energy ◽  
Space Shuttle ◽  
Space Station ◽  
Low Earth Orbit ◽  
Experimental Results ◽  
Earth Orbit ◽  
Material Erosion ◽  
Low Altitude

AbstractThe role of N2 in the upper atmosphere on the atomic oxygen (AO)-induced erosion of polyimide in low Earth orbit (LEO) and sub-LEO is investigated through ground-based experiments and flight data. The experiment is performed by adding an Ar beam at the same collision energy as an undecomposed O2 component in the AO beam formed by laser detonation to simulate the physical effect of simultaneous N2 collision in sub-LEO. The Ar beam is added by the dual-pulsed supersonic valve-equipped laser-detonation system developed at Kobe University. The experimental results indicate that the erosion of polyimide in the laser-detonation system is promoted by the presence of O2 and Ar in the beam, corresponding to N2 in the sub-LEO. On-ground experimental results are compared with in-orbit AO measurements. Previous space shuttle, international space station-based exposure experiments, as well as the world’s first real-time sub-LEO material erosion data aboard a super low altitude test satellite (SLATS) orbiting at an altitude of 216.8 km are presented. The SLATS data suggests the presence of an acceleration effect by N2 collision on AO-induced polyimide erosion, as predicted by ground-based experiments.

Planning for a Space Station

1985 ◽  
Vol 107 (1) ◽  
pp. 7-16
Author(s):  
M. B. Nolan ◽  
E. B. Pritchard
Keyword(s):  
Technology Development ◽  
Space Shuttle ◽  
Space Station ◽  
The United States ◽  
Low Earth Orbit ◽  
Earth Orbit ◽  
Space Systems ◽  
Efficient Access ◽  
Current Assessment ◽  
Future Plans

The Space Shuttle, as the keystone of the United States Space Program, is providing routine and efficient access to and return from low Earth orbit. The next major space initiative must build on and complement these existing space systems while significantly enhancing the national capabilities for routine and efficient operations in space. Past and current studies indicate that a permanent research and operations base in low Earth orbit is the correct next step for NASA to pursue. The operations and research base, as currently perceived, is a combination of manned and unmanned facilities located in low Earth orbit and interconnected by teleoperated transportation stages. A Space Station thus provides new and unique operational and research opportunities that complement the capabilities of the Space Shuttle principally by removing the constraint of time from future mission planning. The current assessment of requirements in the areas of science and applications, commercial utilization, technology development, and national security are discussed. The paper concludes with a discussion of the future plans within the Space Station Program.

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.

A Magnetically Filtered Atomic Oxygen Plasma Source for Low-Earth-Orbit Simulation

2021 ◽  
pp. 1-10
Author(s):  
Carlos A. Maldonado ◽  
Andrew D. Ketsdever ◽  
John D. Williams
Keyword(s):  
Atomic Oxygen ◽  
Oxygen Plasma ◽  
Plasma Source ◽  
Low Earth Orbit ◽  
Earth Orbit
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