ORBCOMM constellation operations approach

In early April 1995, Orbital Sciences successfully launched and deployed the first two ORBCOMM satellites, Flight Model 1 and 2 (FM1, FM2). Since their deployment several thousand data messages have been sent and received utilizing the communications hardware on board the satellite, as well as ground based equipment. These are the first two satellites of a low Earth orbit constellation that could number up to 36 satellites in 6 different orbit planes. From the operation of ORBCOMM FM1 and FM2 satellites, many lessons have been learned on how to operate a constellation of satellites. All of the on-board satellite systems have been thoroughly tested and the results are being incorporated into modifications for the constellation satellites. The ground system has also undergone significant testing and checkout during the early operations of FM1 and FM2. The several deficiencies and problems that have been identified are being addressed in the design of the Satellite Control Center for the ORBCOMM constellation