Investigating the Power Budget of a 3U Nanosatellite Designed for Earth Observation

The Electrical Power System (EPS) is one of the most critical subsystems of a nanosatellite. Thus, its design should be done carefully for a successful mission. To verify that the power needs of its subsystems does not exceed the power available, a power budget should be established. The purpose of this work is to evaluate the 3U nanosatellite's EPS by analyzing its power budget using Systems Tool Kit (STK) software. In this study, the orbital design, the sizing of the PV panels and the batteries used are presented. The simulation is done taking into account the worst case assumptions: the sun-synchronous Low Earth Orbit (LEO) orbit with the longest eclipse period, the worst case solar irradiance of 1316 W/m2. The results of the power budget established confirm the selection and the sizing of PV panels and the batteries.