Estimation of Thermal and Stochastic Variations of Chip Scale Atomic Clocks for Navigation of a Lunar CubeSat

Chip Scale Atomic Clocks (CSAC) have the potential to support one-way radiometric tracking capabilities for CubeSat missions. This work presents a high-fidelity simulation, using the Jet Propulsions Laboratory’s (JPL) Mission Analysis, Operations and Navigation Toolkit (MONTE), testing the performance of CSAC-driven one-way navigation for a CubeSat. A lunar mission was selected, modelled after the planned lunar-orbiting CubeSats to be released during the Artemis-1 flight. Error sources typical for lunar orbiters, as well as tracking schedules and measurement quality expected for a lunar CubeSat are incorporated into the simulation. CSAC errors, with a thermal variation due to lunar eclipse times, are added to the measurements and the CSAC clock states are estimated alongside the spacecraft ephemeris and other error states. The results show that using CSAC-driven one-way navigation, position resolution of hundreds of meters and velocity resolution of tens of cm/s are achievable. This performance is conditioned on the complexity of a lunar mission, due to the highly elliptical orbit and significant temperature changes during orbit.