Work done by @Adnan Machado in October 2024
The satellite’s only power source is the sun. We’re using 18 solar cells separated into 3 solar panels (FINCH-Power-SolarPower). We need to be able to estimate what the power and energy output of the solar panels is over the course of an orbit under multiple attitude modes.
Estimates are done using an analytical approach, and using STK simulations. The STK simulation is expected to result in higher power generation estimates as the analytical model does not account for power generated from solar radiation reflected by the earth. The mathematical model is linked below.
Solar Panel Exposure During Various Attitude Modes
FINCH-Spacecraft-OrbitParameters
Screenshot of orbital parameters used in the STK simulation
Example STK animation of tumbling about the z-axis. For more animations, see the mathematical model
The average power generation estimates are detailed in this google sheet
https://docs.google.com/spreadsheets/d/1bnq7fNa0Se_zQNxVIs5Od6WYnUV59Gj6HwBwuDkie0I/edit?gid=0#gid=0
Most cases have a low (>5% error in the hand calculated average wattage estimates vs the STK sim), however there is a high 24% difference for the nadir y case. The hand calcs consistently give a lower power estimate. This is likely due to the mathematical model not accounting for the sun reflected off the earth. The variation in errors in different cases agrees with this explanation. For example: