Spacecraft Potential Control

The objective of this contract is to develop improved numeric algorithms for the computation of spacecraft charging on earth orbiting spacecraft. This work is part of the Nascap2k program. which is a joint program with the Space Environment Effects (SEE) program at NASA/MSFC. The end result of the program will be a set of user friendly computer codes that compute spacecraft charging in all environments. This interim report describes the development of a computer code that computes spacecraft charging using the Boundary Element Method (BEM) and the development of the Object Toolkit which is used to define spacecraft geometry and materials for Nascap2k. The algorithms contained in the BEM charging are described here. Nascap2k was tested and expanded by doing spacecraft charging calculations in Support of the STEREO mission. A description of these calculations is included. Finally, this report describes a prototype Rapid Alert Charging Tool that uses geosynchronous environmental information to predict spacecraft charging.