Accession Number : AD0732917

Title :   Sensitivity of Thermal Surface Solar Absorptance to Particulate Contamination.

Descriptive Note : Rept. for Dec 69-Dec 70,

Corporate Author : AEROSPACE CORP EL SEGUNDO CALIF ENGINEERING SCIENCE OPERATIONS

Personal Author(s) : Hamberg,Otto ; Tomlinson,Frank D.

Report Date : 30 JUN 1971

Pagination or Media Count : 16

Abstract : The sensitivity of thermal surface solar absorptance to particulate contamination was evaluated. Experiments were conducted using a mirror surface which was incrementally obscured with a limited number of contaminant types and sizes. Aluminum oxide and fly ash particles were selected to bound high and low contaminant reflectance extremes. Size sensitivity was demonstrated by using 3- and 20-micron aluminum oxide particles. Measurements were made of the obscured surface areas and the corresponding changes in reflectance. From these, the related solar absorptance changes were derived analytically. The changes in absorptance indicated high sensitivity to contaminant composition and quantity, low sensitivity to particle size, and linearity with obscured area. (Author)

Descriptors :   (*MIRRORS, REFLECTIVITY), (*SPACECRAFT COMPONENTS, TEMPERATURE SENSITIVE ELEMENTS), (*SOLAR RADIATION, ABSORPTION), IMPURITIES, SURFACES, DUST

Subject Categories : Optics
      Unmanned Spacecraft

Distribution Statement : APPROVED FOR PUBLIC RELEASE