A computer program performs a unified analysis of the radiation exposure, the temperatures, and the power generation and distribution for predicting the performance of the TOPEX satellite on orbit and during maneuvers. The unified analysis is needed because all aspects are interdependent. The power-generating capacity of the solar array of the satellite depends on both the impinging radiation fluxes and the temperatures of the panels. The temperatures, in turn, depend on the power output of the array in addition to the radiation fluxes. Only by considering electric-power generation and consumption, radiation fluxes, and temperatures together can one predict any one of them as well as the state of charge, the voltage, and the current of the batteries. The present computer program predicts the power profile and the solar, albedo, and infrared fluxes on all surfaces of the satellite. It calculates the temperatures of the solar array and its power-generating capacity as function of radiation exposure and temperature. Battery currents and voltages are determined on the basis of the calculated state of charge of the batteries and the power-generating capacity of the solar array as a function of its radiation exposure and its temperatures. All pertinent values are stored in files with any desired time interval.

This program was written by Robert Richter of Caltech for NASA's Jet Propulsion Laboratory. For further information, access the Technical Support Package (TSP) free on-line at www.nasatech.com/tsp under the Software category.

This software is available for commercial licensing. Please contact Don Hart of the California Institute of Technology at (818) 393-3425. Refer to NPO-21018.