Implementation and test of a partial array shunt system for two Small Explorer spacecraft

A power system which utilizes a partial array shunt has been designed and built for two new Small Explorer (SMEX) scientific satellites. The power system topology is significantly changed from earlier SMEX spacecraft which carried full array shunt systems. The first application of the new SMEX power system is for the Transition Region And Coronal Explorer (TRACE) mission. This new power system development included higher fidelity solar array hardware and software to allow integrated ground testing that more closely matches actual on-orbit operating modes. Also, existing airborne support equipment for use on the L1011 Pegasus launch platform has been modified to provide full spacecraft power system functional testing just prior to launch. The implementation and test of the new SMEX power system and associated electrical ground/airborne equipment for the TRACE mission is presented in this paper. Results of functional tests on the TRACE spacecraft have demonstrated robust control stability of the new SMEX power system design under varying spacecraft power profiles and good fidelity in the new test system