Software for Simulation and Control of Tethered Satellite Clusters

There is currently considerable interest in flying many small satellites in a cluster. Indeed, satellite formation flight offers many advantages in allowing high-resolution interferometry, permitting multiple distributed measurements, reducing mission cost and increasing flexibility. Unfortunately, there are long-term perturbation effects that tend to cause satellites in the constellation to be pulled apart. These can be countered by propulsive means at the cost of reducing the lifetime of the cluster. An alternative approach to this problem is to link them together by a system of flexible tethers, held taut by rotation of the entire system. This eliminates the relative navigation problem, and avoids having to keep satellites in the correct relative positions propulsively. In addition, it allows configurations that are not achievable by free-flying spacecraft, limited as they are by the nature of orbital mechanics. The objective of the proposed Phase I work is to develop analysis techniques that will allow tethered satellite systems to be considered for clustered satellite missions; at present, such tools are not available.