Hosted Communications Payload to Leverage Commercial LEO Constellations

A number of satellite communications (SATCOM) constellations have recently been proposed. Because some are funded to initial deployment, it is likely that opportunities to host NASA payloads on these commercial constellations will soon appear. If a tactical communications payload can be hosted by these constellations, the constellation infrastructure can be leveraged as a backbone for tactical communications. These constellations therefore offer the opportunity to provide increased resilience of communications links by delivering diversity of communications coverage and/or dramatically increased tactical communications capacity which can be made available on demand.The SATCOM constellations of most interest are Low Earth Orbit (LEO) and Medium Earth Orbit (MEO) because they have the lowest launch and operations costs, have best coverage (they contain many satellites), and best link budgets. However, such orbits add complexity to the hosted tactical communications payload design and operation, since the satellite will pass over a user terminal which may not have the ability to track the satellite with its antenna.