MULTIRATE NUMERICAL-INTEGRATION OF SATELLITE ORBITS FOR INCREASED COMPUTATIONAL-EFFICIENCY

A multi-rate numerical integration method is applied which allows the direct effect of particular force model components on a satellite's or bital state to be estimated separately from the effects of the remaini ng forces on the satellite. The method allows the quickly changing fea tures of a particular force model component to be sampled without the cost of frequent evaluations of the entire force model. The extra equa tions which this method generates are coupled with the standard equati ons so that the indirect effects of the force model component are not lost. This approach is tested on a LAGEOS II orbit using solar radiati on pressure which has quickly changing penumbral effects.