AAS 96-212

A SYMPLETIC MAP FOR GEOSYNCHRONOUS ORBIT PROPAGATION

A. A. Jackson, NASA Johnson Space Center

Abstract

Long time orbit propagation for objects at geosynchronous orbit altitudes is problem of interest to the orbital debris group at NASA JSC. We have found substantial improvement in speed and accuracy are possible using an integration method specifically designed for motion that is Hamilitonian and nearly Keplerian. We are thus exploring the recently developed techniques of symplectic numerical integration. This method preserves the conservation of Poincare invariants and therefore avoids the spurious dampings or excitations that can be introduced by non-symplectic integrators. The model includes non-spherical gravitational harmonics, the effects of the sun and moon, and radiation pressure. Orbit propagations have been compared with a high accuracy implicit Runge Kutta numerical integrator. Comparison cases for speed and accuracy are presented.