Software for an Autonomous Constellation of Satellites

The Autonomous Sciencecraft Constellation (ASC) software has been developed for Techsat-21 — a group of small satellites, to be launched by the Air Force Research Laboratory in 2004, intended to demonstrate the feasibility of groups of satellites cooperating in the performance of tasks. The task in this initial application will be scientific radar observations of the Earth, using the satellites flying in precise formation to synthesize a wide-aperture antenna. The ASC software will enable Techsat-21 to function with a high degree of autonomy, thereby reducing the utilization of limited communication bandwidth and reducing the need for labor-intensive sequencing of commands and analysis of scientific data on the ground. The software will provide onboard scientific analysis of image data, replanning, robust execution of plans, model-based estimation and control, and formation-flying control to increase science return through a combination of intelligent selection of downlinks and autonomous retargeting on the basis of “interesting” features in the scientific data.