Accession Number:

ADA429735

Title:

Survey of DSCS-III B-7 Differential Surface Charging

Descriptive Note:

Journal article

Corporate Author:

AIR FORCE RESEARCH LAB HANSCOM AFB MA SPACE VEHICLES DIRECTORATE

Report Date:

2004-07-19

Pagination or Media Count:

10.0

Abstract:

An analysis of differential charging between dielectric surface materials and the frame of a DSCS-III geosynchronous spacecraft is presented. Charging levels measured by surface potential monitors SPMs covered with samples of Kapton and Astroquartz have been recorded for one half of a solar cycle. Both seasonal and solar cycle effects are seen in the daily peak levels of the SPM voltages, with local maxima occurring near the equinoxes and a general trend increasing as solar max is approached. Charge neutralization by an onboard Xe plasma contractor was demonstrated to be effective throughout the mission, with a mean voltage reduction of 86 for Astroquartz and 74 for Kapton. Though a statistical analysis shows a general correlation between the fluence of charging electrons with SPM voltages, the event-specific correlation contains enough variance to cast doubt on the usefulness of an electron sensor as a differential charging alarm. We have found that a Kapton-covered SPM may be better suited than an electron sensor as a differential charging alarm.

Subject Categories:

  • Astronautics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE