Experimentally validating the use of in-orbit Global Navigation Satellite Systems (GNSS) receivers within the Space Service Volume (SSV) has been accomplished at LEO, MEO, and GEO altitudes respectively. Therefore, the most recent missions have revealed the GNSS performance at distances of approximately 150,000 kilometers away from the surface of the Earth. The study of Earth GNSS signals beyond such an altitude is still a matter of research, and it is primarily based on modeling and extrapolation from the experience of using GNSS on both the surface of the Earth and on lower orbits. The Lunar GNSS Receiver Experiment (LuGRE) is a payload that will be carried by the Firefly Blue Ghost Mission 1 and will be a joint effort between NASA and the Italian Space Agency (ASI).