Analysis of Multi-GNSS Signal Visibility Throughout a Representative Ballistic Lunar Transfer Scenario

<title>Abstract</title> The increasing volume of space missions expected over the coming decades will drive demand for autonomous navigation methods that can reduce reliance on terrestrial tracking networks. Several research efforts have shown that global navigation satellite systems (GNSSs) can be used to navigate Earth-orbiting spacecraft at altitudes well beyond the GNSS constellations themselves and show great promise as a means of autonomous navigation for spacecraft in cislunar space and at the Moon. This work analyzes the GNSS signal visibility achievable by a high-sensitivity receiver throughout a ballistic lunar transfer (BLT), a highly efficient lunar transfer trajectory in which spacecraft fly to a maximum altitude of approximately four times the Earth–Moon distance over the course of roughly four months. The multi-GNSS signal visibility in the L1 and L5 bands across all currently operational constellations is analyzed throughout the BLT flown by NASA’s Cislunar Autonomous Positioning System Technology Operations and Navigation Experiment (CAPSTONE) mission. Publicly available GNSS transmit antenna pattern data from the Global Positioning System, Galileo, BeiDou Navigation Satellite System, and Quasi-Zenith Satellite System are used.