The thesis investigates the feasibility of duty cycling the GPS receiver onboard small satellites like NPSAT1 in order to repurpose power savings in ways that would better serve the satellite’s mission. Orbital propagation software run on onboard computer hardware produces accurate ephemeris data over short periods without continued GPS input. Longer periods relying on propagator ephemeris translate to greater power savings, but it also means increasing positional error. In order to better define the trade space between time and error of common propagators, Systems Tool Kit software was used to test the accuracy of the Two-Body and Simplified General Perturbations-4 propagators over time against positions measured by the Joint Space Operations Center. Two-Body propagators’ error response varies as a function of altitude and inclination, with the worst case requiring GPS updates up to twice an orbit. Simplified General Perturbations-4 propagators’ error depends strongly on the accuracy of the B* drag term, but is still sufficiently accurate to operate a day or more without a GPS update. Savings in the GPS power budget were found to exceed 96% and 99% for Two-Body and Simplified General Perturbations-4 propagators, respectively, and should be considered for use in future satellites.

Approved for public release; distribution is unlimited.

Includes supplementary material

Lieutenant, United States Navy