GOES-R is the first unclassified mission that will use GPS at HEO. If the GPS tracking proves successful in that orbit, this opens a whole new regime for GPS tracking, and the current commercial GPS simulators on the market can not adequately address these orbits. The potential applications outside of NASA mirror those inside, but on a much larger scale. Laboratories and universities would have ready access to a low-cost simulation capability that can be customized for their needs. For example, GPS simulation equipment currently tagged at $250,000 could be replaced with MRSiG and a SDR receiver for less than 1/10 the price, opening the door to smaller institutions while encouraging development and innovation. Similar arguments can be made for the modeling of spacecraft communications systems, TDRSS modeling, or most wireless communication systems. MRSiG will be able to replace many of the expensive, highly specialized RF signal generators with cheaper generic boxes that can be customized as the technologies are updated. MRSiG boxes can be utilized throughout the entire RF hardware development cycle, from the breadboard to the flight stages. Their relatively low cost point will allow more simulators in the labs, and less resource contention for developing projects. The portability of the MRSiG allows testing outside the lab, including environmental test chambers and during spacecraft integration. In particular, MRSiG could be utilized as a GPS simulator, replacing the Spirent GPS signal generators currently in use. As the Constellation program continues to ramp up, these boxes could be utilized to simulate anything from lunar ground communication, ground-lunar relay communication, and even lunar to Earth communications. MRSiG could potentially be instrumental in performing formation flying or rendezvous and docking simulations if RF data is exchanged.