Cluster flight for SAMSON using differential drag

The idea to use differential drag (DD) for satellite formationkeeping emerged in the mid-Eighties, when the feasibility of DD-based control was proven assuming linearized relative dynamics for two satellites. Although almost three decades have passed, the most prevalent approach for investigating DD-based formationkeeping still utilizes linear models written for only a pair of satellites. However, such models are not adequate for long-term cluster flight of multiple satellites or multiple modules forming, e.g., a disaggregated satellite, with typical mission lifetimes exceeding a year. In the current work, an alternative, nonlinear method for DD-based cluster-keeping is developed. The method relies on orbital elements instead of Cartesian coordinates. The results are verified using simulations based on the forthcoming Space Autonomous Mission for Swarming and Geolocation with Nanosatellites.