Accession Number:

ADA008504

Title:

Spacecraft Self-Contamination by Molecular Outgassing

Descriptive Note:

Technical note

Corporate Author:

MASSACHUSETTS INST OF TECH LEXINGTON LINCOLN LAB

Personal Author(s):

• Harvey, Robert L.

Report Date:

1975-03-31

Pagination or Media Count:

65.0

Abstract:

The contamination of spacecraft surfaces from ambient and outgassing molecules is considered. A model is formulated for the molecules desorbed from the spacecraft surfaces and scattered by the ambient molecules back to the emitting and adjacent surfaces. Equations are derived for the backscatter and far-field cases as a function of surface geometry, mean free path, and desorbing beam shape. Expressions are given for point to point and flat surface to point scattering. The scattered molecular irradiance is combined with other sources to obtain the total molecular irradiance. A calculation of the contamination during launch of the Lincoln Experimental Satellites 8 and 9 is given.

Descriptors:

• *SPACECRAFT
• *DESORPTION
• *CONTAMINATION
• *OUTGASSING
• PARTICLE COLLISIONS
• MOLECULES
• SCATTERING
• SURFACES

Subject Categories:

• Physical Chemistry
• Unmanned Spacecraft

Distribution Statement:

APPROVED FOR PUBLIC RELEASE