Accession Number : AD0655425

Title :   ANALYSIS OF TIME-DELAY MAGNETIC DAMPING OF SPACECRAFT LIBRATIONS IN NEAR-SYNCHRONOUS EQUATORIAL ORBITS.

Descriptive Note : Technical memorandum,

Corporate Author : JOHNS HOPKINS UNIV SILVER SPRING MD APPLIED PHYSICS LAB

Personal Author(s) : Mackison,D. L.

Report Date : JUN 1967

Pagination or Media Count : 51

Abstract : Time-lag magnetic damping provides a method of using the earth's magnetic field for rapid libration damping of satellites when the field strength is insufficient to dissipate energy with magnetic hysteresis material. This consists of generating a spacecraft-fixed magnetic dipole, initially parallel to the earth's magnetic field, and holding it constant as the spacecraft librates. When the magnet is turned off, a portion of the satellite's angular momentum has been transferred to the earth's magnetic field. A mathematical model is developed relating the dipole moment, the dipole holding time, and the initial attitude to the energy dissipation rate. Comparisons are made between the results predicted analytically by the damping model and those obtained by numerical integration of the differential equations of attitude motion. (Author)

Descriptors :   (*TIME LAG THEORY, *MATHEMATICAL MODELS), (*EARTH(PLANET), MAGNETIC FIELDS), HYSTERESIS, SPACECRAFT, ROTATION, DIFFERENTIAL EQUATIONS, MOTION, MOMENTUM, DIPOLE MOMENTS, DAMPING, OSCILLATION, SATELLITE ATTITUDE

Subject Categories : Astronautics

Distribution Statement : APPROVED FOR PUBLIC RELEASE