Accession Number : AD0475737


Title :   SPIN DECAY OF A FLEXIBLE SATELLITE BY STRUCTURAL DISSIPATION OF ENERGY,


Corporate Author : TORONTO UNIV DOWNSVIEW (ONTARIO) INST FOR AEROSPACE STUDIES


Personal Author(s) : Etkin, Bernard


Report Date : Mar 1965


Pagination or Media Count : 34


Abstract : This report analyzes the coupling of the rigid-body and elastic modes of motion of a spinning satellite under two conditions of motion: (1) wobbling, in which the direction of the spin vector is appreciably different from that of a principal axis of inertia and (2) quasi-steady spin, in which the spin vector nearly coincides with the principal axis of maximum inertia. In the former case, elastic modes are excited into periodic motion, with consequent energy dissipation, even in the absence of an external force field. In the latter case the elastic mode excitation is caused by, and requires the presence of, the external gravity-gradient field. Order-of-magnitude estimates of the rate of energy dissipation and spin decay are presented for both cases for the Alouette 1 satellite. It is concluded that the mechanism studied is not the principal one causing the spin decay of Alouette 1 satellite. (Author)


Descriptors :   *ARTIFICIAL SATELLITES , *SPINNING(MOTION) , MOTION , DAMPING , FLEXIBLE STRUCTURES , EQUATIONS OF MOTION , ELASTIC PROPERTIES , MATHEMATICAL ANALYSIS , DYNAMICS , SPACE FLIGHT , ORBITS , DIFFERENTIAL EQUATIONS , MOMENTS , ROTATION , STRAIN(MECHANICS) , SCIENTIFIC SATELLITES , LOAD DISTRIBUTION , ENERGY , HYSTERESIS , MECHANICAL PROPERTIES , GRAVITY , DEFORMATION , BOOMS(EQUIPMENT) , MOMENT OF INERTIA


Subject Categories : Mechanics
      Unmanned Spacecraft


Distribution Statement : APPROVED FOR PUBLIC RELEASE