Accession Number : AD0716772

Title :   Gravity-Gradient Stabilization Studies with the Dodge Satellite.

Descriptive Note : Technical memo.,

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

Personal Author(s) : Fischell,Robert E. ; Mobley,Frederick F.

Report Date : APR 1970

Pagination or Media Count : 51

Abstract : The DODGE satellite was launched on 1 July 1967 into a near-synchronous orbit to demonstrate gravity-gradient stabilization at that high altitude and to experiment with various design parameters and damping techniques. This satellite was the first to be three-axis stabilized at high altitude using gravity-gradient techniques. It continues to function satisfactorily to the present date. Stabilization in pitch and roll to better than plus or minus 10 degrees has been obtained. The yaw stabilization of plus or minus 45 degrees has been fairly consistent; with the assistance of a small angular momentum flywheel, yaw accuracy of plus or minus 20 degrees was achieved. Magnetic damping of the sample-and-hold type and simulated hysteresis were both successful in damping librations. Efforts with the torsion-wire-suspended damper boom scheme were not successful, probably because of a mechanical bias in the device. A television camera system permitted observation of the boom bending under the influence of solar heating. Mechanical hysteresis in the boom bending was observed. (Author)

Descriptors :   (*SCIENTIFIC SATELLITES, STABILIZATION SYSTEMS), GRAVITY, HYSTERESIS, DAMPING, BOOMS(EQUIPMENT), SOLAR RADIATION, TELEVISION CAMERAS, STABILITY, STATISTICAL DATA

Subject Categories : Spacecraft Trajectories and Reentry

Distribution Statement : APPROVED FOR PUBLIC RELEASE