AAS 97-736

A NEW METHOD OF DETERMINING ORBIT LIFETIME PROBABILITIES FOR USE IN PLANETARY PROTECTION ANALYSIS

M.A. Vincent - Jet Propulsion Laboratory

Abstract

A new statistical method was derived to model the long-term behavior of the Martian atmosphere and its effect on a satellite's orbital lifetime. It was successfully used to lower the requirement for the initial quarantine orbit for the Mars Global Surveyor mission to 427 km from the 450 km dictated using conventional methods. A detailed description of the general method will be presented along with how it fits in with the general propagation models used for mission design. The results for MGS will be presented for a variety of input parameters and modeling assumptions. Discussions of future applications include other missions and completely different fields such as species extinction in ecology.