Autonomous Optical Navigation for Planetary Orbiters

Using standard spacecraft attitude determination sensors, in particular a star sensor and planet sensors, an autonomous navigation system will be developed for planetary orbiters, offering absolute navigation accuracy on the order of ?100 m. This capability directly supports automated rendezvous and docking missions in Earth orbit as well as at other solar system bodies, such as Mars. The navigation solution depends only on measurements of the distance to the center of the central body, determined by measuring its angular diameter, and the direction to the center of the body in inertial space. These measurements are made by imaging the planetary disk, determining its centroid and angular diameter, and simultaneously imaging the star background. Relative navigation between chaser and target spacecraft is achieved via intersatellite communication of each individual vehicle?s absolute navigation solution. Microcosm offers substantial experience in autonomous space navigation, including our development of an optical autonomous navigation system for the Air Force, which was flown on the TAOS spacecraft in 1994. Microcosm is also involved in ongoing work through the USAF to develop an autonomous rendezvous and docking capability for on-orbit servicing of Earth orbiters.