Accession Number : ADA132031

Title :   Spacecraft Charging at Geosynchronous Orbit and Large Scale Electric Fields in the High Latitude Ionosphere.

Descriptive Note : Final rept. 1 Oct 78-30 Sep 81,

Corporate Author : BOSTON COLL CHESTNUT HILL MA DEPT OF PHYSICS

Personal Author(s) : Feynman,Joan ; Burke,William J

PDF Url : ADA132031

Report Date : 30 Sep 1981

Pagination or Media Count : 213

Abstract : Problems pertaining to spacecraft charging at near-geosynchronous orbit were investigated using data from P78-2 SCATHA collected in 1979-80. These studies included specification of significant aspects of the near-geosynchronous environment, effectiveness of active control systems and verification of computer modeling of satellite potentials. Environmental specification studies were made of major plasma sheet boundaries, near-geosynchronous particle fluxes and long term prediction of hazardous geomagnetic conditions. Work was begun on magnetospheric modeling. Unfortunately, the particle beam active control system caused the failure of two instruments. These events were thoroughtly studied but some uncertainty remains concerning the causes of the problems. Comparisons of spacecraft discharge techniques indicated the x sub e (+) plasma source was the preferred operational mode. Satisfactory agreement with observed charging levels was obtained when the NASCAP/AFGL computer model was used with environmental input derived from observed particle fluxes. A secondary research effort focused on studies of ionosphere-magnetosphere interactions in the polar cap and auroral zone. Air Force measurements of S3-2 electric and magnetic fields and electron and thermal plasma fluxes were used as well as DMSP auroral imagery.

Descriptors :   *SPACE CHARGE, *SPACECRAFT, IONOSPHERE, ELECTRIC FIELDS, HIGH LATITUDES, SYNCHRONOUS SATELLITES, ORBITS

Subject Categories : Unmanned Spacecraft
      Spacecraft Trajectories and Reentry

Distribution Statement : APPROVED FOR PUBLIC RELEASE