ESA GNC Conference Papers Repository
Convex Guidance for Close Rendezvous Operations in Cislunar Near Rectilinear Halo Orbits
The future of Human Spaceflight exploration points towards complex missions designed around the Earth-Moon Lagrangian points. The Lunar Gateway, assembled in a Near Rectilinear Halo Orbit about the second Earth-Moon Lagrangian point, will provide easier access to the Moon surface and facilitate further exploration of the solar system. Rendezvous and Docking operations are critical for the maintenance and assembly of such a complex infrastructure. The scope of this research is to apply successive convexification and convex optimization methods to design on-board autonomous Close Rendezvous guidance about NRHOs with a focus on the rendezvous between the Orion Multi-Purpose Crew Vehicle and the Gateway. The proposed trajectories reflect real mission constraints and follow the international RVD interoperability standards. This paper highlights how to express and convexify the main dynamics and constraints involved in a cislunar RVD scenario and includes free drift constraints at hold points within the guidance synthesis to design passively safe trajectories. The result is an algorithm that outputs a 6-degree-of-freedom guidance profile for the chaser in translation and attitude motion and that can be used as a design tool while performing trade studies for autonomous rendezvous on NRHOs.