Low earth orbit satellite constellation stationkeeping algorithm with absolute altitude control

Abstract

An easily implementable satellite constellation stationkeeping algorithm for maintaining the relative positioning among satellites of a low earth orbit constellation with minimal maneuvering while maintaining the constellation altitude over the effects of atmospheric drag. The satellite constellation stationkeeping algorithm may be implemented as a system or method that uses atmospheric drag perturbations to extend the stationkeeping cycle of the satellites in the low earth orbit constellation while simplifying the implementation algorithm and performing minimal maneuvers. In an exemplary satellite constellation stationkeeping algorithm, a plurality of satellites or a ground station are configured with a controller that implements an absolute altitude control algorithm. The plurality of satellites are launched into a respective plurality of slots of a low earth orbit. The orbital position of each satellite is controlled using the absolute altitude control algorithm such that each satellite is allowed to drift to or near the edge of a positional box that defines its slot, and the altitude of each satellite is selectively driven to a fixed target altitude which is a function of position and drag, using one or more thrusters for example, to reverse the satellite drift in its slot. During normal operating conditions, the orbital position of each satellite is controlled using only posigrade thrusting implemented by the thrusters.