Formation sensing and control technologies for a separated spacecraft interferometer

Describes spacecraft formation control and sensing research with application to a separated spacecraft interferometer. A multi-layer control design that achieves very accurate alignment between spacecraft is described. Sensing for this control architecture is based on a global real-time relative position and orientation estimator that uses carrier differential-phase GPS measurements. A local optical sensor is used as well. The experiments are performed on a fully functional indoor GPS environment using three prototype spacecraft on a granite table. Work continues on extending the control to a formation of three active vehicles and on extending the sensing system to a self-constellation.