RADIATION-PRESSURE AND AIR-DRAG EFFECTS ON THE ORBIT OF THE BALLOON SATELLITE 1963 30D

摘要

Computed orbits of the balloon satellite 1963 30D arc given every 2 days over an interval of 456 days near the beginning of the satellite's lifetime and an interval of 824 days near the end of its lifetime. The effects of radiation pressure on the satellite arc examined in some detail. It is found that the variations in all the elements can be represented by use of a single parameter to specify the effect of diffuse reflection from the satellite's surface, and that this parameter remains constant, or nearly so, during the entire 7-year lifetime. Success in obtaining a consistent representation of the radiation-pressure effects is ascribed to the inclusion of the effects of terrestrial radiation pressure, using a model for the earth's albedo that includes seasonal and latitudinal variations. "Anomalous" effects in the orbital acceleration, as well as in the other elements, are represented quite well by including a small force at right angles to the solar direction and by allowing this to rotate about the solar direction. This implies that the satellite is spherical, that it is rotating, and that the axis of rotation process’s. While the period of precession decreases considerably over the lifetime, the magnitude of the right-angle force remains essentially constant at about 3% of the total force.