Amazon.com, Inc.
System for maintaining satellites in orbital configuration

Abstract:

A constellation of many satellites are actively maneuvered to maintain specified non-geosynchronous reference orbits. Each satellite is assigned a slot within a particular reference orbit. For each reference orbit, a set of orbital parameters including eccentricity and argument of perigee for frozen orbits are selected that are unique relative to other reference orbits in use. One characteristic of a frozen orbit is that at a given point in the orbit, altitude is relatively constant. At points where orbital planes of the reference orbits intersect, the differing sets of orbital parameters assure a vertical separation between satellites in different orbital planes is maintained without the need for evasive maneuvers. Actual orbital motion data is obtained from sensors onboard each satellite. The desired orbital parameters are maintained based on the actual orbital motion data as part of scheduled maneuvers to maintain the reference orbit assigned to that satellite.