Accession Number : ADA191943

Title :   Spacecraft Requirements for Predictions of Geomagnetic Activity (A Tutorial).

Descriptive Note : Technical rept.,

Corporate Author : AEROSPACE CORP EL SEGUNDO CA SPACE SCIENCES LAB

Personal Author(s) : Vampola, Alfred L

PDF Url : ADA191943

Report Date : 01 Mar 1988

Pagination or Media Count : 21

Abstract : Operational and research spacecraft require predictions of geomagnetic activity due to various effects of the geomagnetic activity on their operation. At high altitude, electrical charging of spacecraft surfaces, which occurs as a result of hot plasma injected from the geomagnetic tail during substorms, can produce discharges which result in spurious operation of the spacecraft. A reliable prediction of such activity can permit additional vigilance on the part of ground controllers at times of possible spurious operation of the spacecraft. Large magnetic disturbances, which accelerate electrons to high energies in the magnetosphere, increase backgrounds in sensors such as star sensors used for attitude control and also can produce spurious operation through the mechanism of thick dielectric charging which also produces discharge pulses. Again, reliable prediction of such magnetic storms, which requires a knowledge of solar wind conditions, would be of great value in operational management of space assets. For low altitude spacecraft which are subject to orbit perturbations as a result of changes in atmospheric scale height, constituent density, and temperature, operational procedures can also benefit from a predictive capability of geomagnetic activity which is closely linked to modifications of the atmospheric density profile.

Descriptors :   *ATMOSPHERIC DENSITY, *MAGNETIC DISTURBANCES, *PERTURBATIONS, ATTITUDE CONTROL SYSTEMS, DENSITY, DETECTORS, ELECTRIC CHARGE, ELECTRONS, GEOMAGNETISM, HIGH ALTITUDE, HIGH ENERGY, HIGH TEMPERATURE, LINKAGES, LOW ALTITUDE, MAGNETIC STORMS, MAGNETOSPHERE, MODIFICATION, ORBITS, PLASMAS(PHYSICS), PREDICTIONS, PROFILES, RELIABILITY, REQUIREMENTS, SOLAR WIND, SPACECRAFT, SPURIOUS EFFECTS, STARS, SURFACES, SPACE CHARGE, ELECTRIC DISCHARGES

Subject Categories : Astronautics

Distribution Statement : APPROVED FOR PUBLIC RELEASE