Attitude determination of small spinning spacecraft using three axis magnetometer and solar panels data

An algorithm for attitude determination of a spinning spacecraft in Low Earth Orbit using three axis magnetometer and solar panels data is proposed. With this algorithm, the solar panels necessary for power generation are also used as a sensing system for attitude determination. The algorithm employs voltage, current and temperature measurements from all of the solar panels to reconstruct the sun direction, which is based on an accurate solar panels mathematical model and requires some data filtering, according to the motion of spinning spacecraft. The sun direction determination accuracy is improved by exploiting a known relationship between sun and magnetic field motion in the spacecraft reference frame. It is shown, by numerical simulation, that the spacecraft attitude can be determined within a few degrees of accuracy in a reasonable time (on the order of one min), which is usually adequate for small, low cost, missions.