Simulating Iridium Satellite Coverage for CubeSats in Low Earth Orbit

This paper will examine the merits of using the Iridium satellite network for duplex inter-satellite communications. The Iridium radio system, relaying data through a 66-satellite constellation in upper LEO, has the potential to provide satellites with superior coverage compared to conventional ground stations. Such stations are limited in range, restricting data downlink and thus the experiments possible on nanosatellites. Use of the Iridium network may therefore be especially appealing for future missions staged in LEO, and specifically for CubeSats due to smaller budgets and shorter lifespans. To satisfy research objectives, simulations run with JSPOC TLEs and SGP4 propagators were used to model the Iridium network and propagate the satellites. Post-hoc validation will be performed by the Thomas Jefferson High School Research and Education Vehicle for the Evaluation of Radio Broadcasts (TJ REVERB) CubeSat mission, scheduled to deploy from the ISS in Q4 of 2018 or Q1 of 2019 as the first non-government-sponsored user of the Iridium satellite radio system for space missions. Future projects requiring similar connectivity could take advantage of the lessons learned, and may utilize the profiles developed in this paper.