Space Vehicle Material and Plume Interactions With the Low Earth Orbital Environment
Abstract
The setup of a UHV apparatus with a hyperthermal 0-atom source was completed, and this apparatus is available as infrastructure for in-situ investigations of surfaces modified by hyperthermal atomic-oxygen. The laser-breakdown, hyperthermal atomic-oxygen source has been dramatically improved by the redesigned molecular beam valve. A quartz crystal microbalance has been used to study the erosion kinetics of a number of P0SS-containing and Al203-coated polyimides during exposure to hyperthermal 0 atoms. Crossed-beams experiments in the PI's lab and corresponding theoretical studies by collaborators have revealed the dynamics of 0(3P) reactions with several small molecules that might be found in rocket exhaust gases. Beam-surface scattering experiments, in which hyperthermal 0 and Ar atoms were directed at fluoropolymer surfaces (with and without the presence of VUV light), found synergistic effects involving 0-atom reactions, VUV light, and collision-induced dissociation that may dominate the mechanism of Teflon degradation in low Earth orbit. The dynamics of hyperthermal Ar scattering from graphite showed the risk of using simple models to interpret hyperthermal gas-surface interactions. The exposure of numerous samples to a beam of hyperthermal oxygen atoms confirmed the 0-atom resistance of several new POSS polymers and deepened our understanding of the erosion mechanisms of polymers. The infrastructure to study hyperthermal interactions has been transitioned to a Center for Laboratory Studies of Rocket Plume Chemistry and to the support of two STTR projects aimed at the development of improved coatings for use in space.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 15, 2008
- Accession Number
- ADA476240
Entities
People
- Timothy K. Minton
Organizations
- Montana State University