Duration: 36 months
ESA with its industrial partners is currently developing a navigation infrastructure within the Moonlight initiative. A Lunar Communications and Navigation System (LCNS) constellation is envisaged and the technical details are becoming concrete. In parallel, similar activities are being conducted by NASA and JAXA and an interoperable combination of these systems is ensured by LunaNet. The combination of this system of navigation systems and highly sensitive GNSS receivers that are being developed such as LuGRE and NC3m, will allow for autonomous operations on and around the Lunar surface.
Within the Artemis programme, human operations on and around the Moon are planned, which mandates a certain level of safety requirements. Astronauts should be confident that their navigation equipment provides them with a position that is not containing faults or will otherwise alert them when the position uncertainty grows. Similarly, the navigation error supplied to orbiters, rovers and autonomous vehicles should be bound so as to avoid erroneous GNC actuation, loss of equipment or worse.
To this end, a study is proposed that evaluates the potential integrity performance of currently synthesized navigation architectures. The study shall focus both on system level as well as user level integrity, analogous to safety-of-life applications such as aviation. At the system level, the implications of surface beacons, multi-constellation and the lunar environment are considered, whereas algorithms such as ARAIM can be implemented at user level. Simulation tools and models currently developed by ESA and contractors for Lunar navigation analysis can be leveraged and extended for the analysis of such integrity layers. These tools can be used to determine both signal-in-space and sensor-fusion error budgets and performance. Based on these simulations, integrity metrics and architectures can be evaluated consolidating the navigation performance requirements of safety critical operations.
