TechSAT attitude control

Abstract

TechSAT is an academic program of the Technion - Israel Institute of Technology. Emphasizing new engineering solutions, it will be a low-cost, sun-synchronized, 3-axis stabilized, nadir-pointing 50-kg microsat, and will be launched by Arianne as a piggyback payload. The satellite is actually a gyrostat, based on a momentum wheel, a static horizon sensor, three magnetotorquers and a 3-axis magnetometer, all especially designed for TechSAT, with total power consumption of under 3 W. The satellite is designed to be released with unknown attitude and with zero stored momentum. The wheel is accelerated to its biased momentum and the body is slowly controlled to become stabilized, using algorithms that utilize magnetometer data only, to an accuracy of 5 deg, which is considered as coarse cruise. Next, fine cruise uses the static horizon sensor, and a final accuracy of 0.1 deg is achieved.