MAGNETIC SAMPLE-AND-HOLD DAMPING OF A GRAVITY-GRADIENT STABILIZED SATELLITE.
Abstract
Sample-and-hold magnetic damping provides a method using the earth's magnetic field for libration damping. A spacecraft-fixed magnetic dipole initially parallel to the earth's magnetic field vector is generated and held constant as the satellite rotates. When the magnet is turned off, a portion of the libration energy is transferred to the earth's magnetic field. A mathematical model of this system is developed for a satellite in a near synchronous equatorial orbit. The DODGE satellite libration during the last quarter of 1967 is compared with its theoretical motion in a time-varying magnetic field. The results indicate that a possible cause of the large attitude motion was the dipole-magnetic field interaction which was near resonance with normal modes of the motion. A criterion is developed for operating the system in closed-loop fashion to insure continuous libration damping. An included example uses actual DODGE attitude data. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Feb 01, 1969
- Accession Number
- AD0686714
Entities
People
- D. L. Mackison
- P. M. Bainum
Organizations
- Johns Hopkins University Applied Physics Laboratory