Query-based attitude control of high-autonomy spacecraft

In August 1993, heavy meteor activity caused the Olympus telecommunications satellite (S/C) to lose attitude reference. The spacecraft's emergency reacquisition mode consumed so much propellant that the mission had to be terminated one year ahead of schedule. The Olympus scenario is a good example of the limited autonomy exhibited by modern spacecraft systems. This paper modifies an adaptive control scheme which can be applied to this problem. The proposed method is a "query-based" adaptive control scheme which uses a cutting-plane algorithm known as the ellipsoid method to identify stabilizing controller gains. The query-based adaptation scheme is demonstrated on a detailed simulation of the the Olympus satellite. The results show that the proposed method is able to identify nominal station keeping controller gains for the Olympus scenario outlined above.