Standard Practice for QCM Measurement of Spacecraft Molecular Contamination in Space

Importancia y uso:

5.1 Spacecraft have consistently had the problem of contamination of thermal control surfaces from line-of-sight warm surfaces on the vehicle, outgassing of materials and subsequent condensation on critical surfaces, such as solar arrays, moving mechanical assemblies, cryogenic insulation schemes, and electrical contacts, control jet effects, and other forms of expelling molecules in a vapor stream. To this has been added the need to protect optical components, either at ambient or cryogenic temperatures, from the minutest deposition of contaminants because of their absorptance, reflectance or scattering characteristics. Much progress has been accomplished in this area, such as the careful testing of each material for outgassing characteristics before the material is used on the spacecraft (following Test Methods E595 and E1559), but measurement and control of critical surfaces during spaceflight still can aid in the determination of location and behavior of outgassing materials.

Subcomité:

E21.05

Volúmen:

15.03

Número ICS:

71.040.99 (Other standards related to analytical chemistry)

Palabras clave:

contamination measurement; molecular contamination; outgassing; outgassing rates; quartz crystal microbalance; spacecraft contamination; temperature controlled quartz crystal microbalance;