Lunar satellite formation keeping using differential solar radiation pressure

Using differential solar radiation pressure (DSRP) for satellite formation keeping is not a new idea. However, there is no existing design methodology of DSRP-based controllers for lunar satellite formation keeping. Lunar orbits are different from low Earth orbits, because the third-body effects are dominant. This paper develops a DSRP-based formation keeping controller, using mean orbital element feedback, for regulating relative distances between satellites in lunar orbits. It is shown that the most effective way to mitigate the intersatellite drift is to adjust the semimajor axes. This is achieved by modifying the cross-sectional areas of the satellites. The stability of the closed-loop system is proven based on the finite time stability theory. Numerical simulation results illustrate that the new DSRP-based controller is able to arrest the relative distance drift in lunar orbits for several years.