Abstract: In a constellation of orbiting satellites (12) in non-geostationary orbits, a failing satellite is replaced with a spare satellite from a spare orbit (53). The satellites (12) are in one of several orbital planes (14) that have an inclination angle with respect to the equator. An orbiting spare satellite located in a monitor orbit (55) is provided for each orbital plane (14). When a failing satellite in the operational orbit is detected, the spare satellite replaces the failing satellite by exchanging positions with the failing satellite. The failing satellite may remain in the monitor orbit to subsequently replace another failing ("sicker") satellite. Accordingly, the satellites that are the "healthiest" are maintained in operation. Cross-links (23) between satellites are maintained minimizing any disruption in communication service when a hole occurs in an orbital plane (14) as a result of a failure.

Abstract: A method and system for formationfinding and formationkeeping in a constellation of satellites (20) orbiting about a primary body (34) is provided. A set of satellite (20) destination position (22) and time goals is selected corresponding to the satellite's (20) station in a desired constellation. The satellite (20) senses actual destination arrival positions (32) and times relative to reference positions independent of the constellation and compares these values to values from the set of goals. Corrective maneuvers are selectively implemented responsive to this comparison.