Analysis of the Orbit of 1966-63A Near 15th-Order Resonance.
ROYAL AIRCRAFT ESTABLISHMENT FARNBOROUGH (ENGLAND)
Pagination or Media Count:
The orbit of 1966-63A had an initial period of 105.12 minutes and slowly contracted under the influence of drag to pass through 15th-order resonance in December 1976. A satellite experiences 15th-order resonance when the track of the satellite over the Earth repeats after 15 revolutions, and if the decay rate is slow enough, an orbit passing through the resonance can be appreciably perturbed by the effects of 15th-order harmonics in the geopotential. Recently 23 resonant orbits, at various inclinations, have been analysed to determine harmonic coefficients of order 15 and degree 15, 16, 17,... 35. The satellite 1966-63A was used in this analysis, the lumped harmonic coefficients being obtained from the analysis of 25 values of inclination from US Navy orbits kindly supplied by the Naval Research Laboratory. The fit of the theoretical curve to the values of inclination was not too satisfactory, and the analysis of the eccentricity was not attempted as the values were not considered accurate enough. The aim of this Report is to compute more accurate and if possible more frequent orbits over the resonant period using the raw observations supplied by the US Navy and the RAE orbit refinement program PROP in the PROP6 version.
- Computer Programming and Software
- Spacecraft Trajectories and Reentry