Long-Duration Low-Thrust Spacecraft Tracking With Sparse Optical Space Surveillance Data

An important task for space object catalog maintenance is to perform maneuver detection and orbit recovery on uncooperative spacecraft. Without known maneuver plan as a priori, the orbit of an uncooperative spacecraft can hardly be determined and predicted during the maneuver period because space surveillance data are usually sparse and short arc. Nowadays, more and more spacecraft equip electric propulsion and perform long-duration low-thrust maneuvers to realize orbital transfer. This poses higher challenges to the research area of space surveillance. In this article, a methodology for long-duration low-thrust spacecraft tracking with sparse optical space surveillance data is developed in the framework of the minimum-energy control problem. With the energy control cost as a metric, tracklet-to-orbit association, sequential tracklet association, and orbital uncertainty characterization are realized during the maneuver period. Herein, the <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">admissible control region</i> is defined to describe a collection of orbits constrained by both optical tracklet and spacecraft maneuvering capability. In addition, the algorithm automatically discriminates the motion mode of the target and accordingly adapts strategies of updating orbital states. Tests with real flight data of the QK-1 spacecraft show that the proposed methodology can realize long-time uninterrupted tracking of low-thrust spacecraft.