Pulsar Navigation for Crewed Exploration of the Solar System, Year 3

The goal of the Pulsar Navigation for Crewed Exploration of the Solar System project was to mature the X-ray/Pulsar Navigation technology for use in crewed missions which will explore the Solar System beyond the Earth-Moon system. One of the major challenges in developing a system which will operate far from planetary bodies is to maintain an accurate navigation state which will allow the vehicle to reach its goal (or equivalently to return the crew to Earth) in the case of loss of communications with the ground. To that end, x-ray navigation is a perfect complement to optical navigation which will allow the vehicle to navigate autonomously to achieve the mission objectives. The challenges addressed in this project was to mature both the hardware and the understanding of how a crewed vehicle can use x-ray navigation outside of Low Earth Orbit (LEO). In the past two years Near Rectilinear Halo Orbit (NRHO) trajectories were used to evaluate the performance of a single x-ray sensor. The results showed that the attitude requirements of using a single x-ray sensor are rather tight; having more than one x-ray sensor working together, either pointed in the same direction or in a different direction will allow for more opportunities to obtain measurements without placing undue burden on the attitude control system. We initiated conversations with Gateway to use it as a platform to mature the hardware and to determine the performance of such a sensor system in cis-lunar space away from Earth.