Evaluation and Testing of the Solar Cell Measurement System Onboard the Naval Postgraduate School Satellite NPSAT1

Abstract

The Naval Postgraduate School Spacecraft Architecture and Technology Demonstration Satellite NPSAT1, launching in the fall of 2006, will include a system to measure the performance of new experimental triple junction solar cells. The measuring circuit used in the system is based on a circuit developed at NPS many years ago. The Solar Cell Measurement System (SMS) will trace the cells’ current-voltage (I-V) curves while in orbit. The System consists of a radiation-hardened microcontroller that uses a radiation-hardened FPGA to monitor a collection of sensors. A current sink circuit is used to measure the current and voltage on the test cells. A total of 24 cells on the satellite will be tested, 22 of which are the experimental cells, and 2 are dual junction cells serving as reference cells. Prior to launch, extensive testing is being performed on the system to ensure proper operation. This paper presents the mission information, system design, test setup, and test results of the SMS.