Lunar far side positioning enabled by a CubeSat system deployed in an Earth-Moon halo orbit

For explorations of the far side of the Moon, it is necessary to tackle the challenge of navigation and communication as the far side is invisible to the Earth. This paper proposes a low-cost mission concept that consists of four CubeSats in an Earth-Moon L₂ (EML2) halo orbit. The mission objective is to provide real-time positioning service for lunar far-side assets, taking advantage of the visibility of EML2 halo orbits to both the Earth and lunar far side. Being miniature, CubeSats can be carried by a mother spacecraft and deployed during the mid-course. As CubeSat missions are generally constrained by limited communication, power, and propulsion capacities, this paper presents a feasibility study that takes into account the high-fidelity dynamical environment and system constraints. This paper analyzes the positioning performance in terms of accuracy, and spatial and temporal coverage. In addition, the requirement of deployment in terms of Δv budget and thrust magnitude is also investigated. Results show that (1) a positioning accuracy of 2.7 km is achievable; and (2) several state-of-the-art propulsion systems can meet the requirement of deployment and the stationkeeping for an acceptable duration.