Off-Nominal Trajectory Design of Earth-NRHO Transfer Orbit for Logistics Resupply Mission to Gateway

Abstract

NASA and other space agencies plan to establish Gateway in Near-Rectilinear Halo Orbit Insertion (NRHO) for near-lunar missions. There are several methods for the transfer trajectory to NRHO. Currently, NASA employs the In-Direct Transfer (IDT) with Powered Lunar Swing By (PLSB) for manned transport with Orion. This paper proposes an off-nominal recovery trajectory using the Perilune Rendezvous Method (PRM). Its time of flight is two weeks longer than IDT, but the required ΔV is lower. There are clear advantages to designing the recovery trajectory using the PRM. The total ΔV in the off-nominal case is less than in the nominal case, and all transfer windows can be designed as recovery trajectories to the NRHO. Also, the availability of at least 25 days to prepare for the next maneuver is an indication of mission robustness. Thus, the PRM provides a practical off-nominal recovery trajectory without reducing cargo volume. This paper presents the design methodology required to generate PRM trajectories. Furthermore, it clarifies the conditions for connecting to the recovery trajectory using PRM, demonstrating its robustness.