Linear Covariance Techniques to Analyze a Multi-Vehicle, Multi-GN&C System with Applications to Rendezvous in a Near Rectilinear Halo Orbit

Typically for a rendezvous and docking scenario, only a single vehicle is considered the
active vehicle. As a result, the target vehicle’s GN&C system is typically not a factor in the
integrated performance analysis as it assumes a passive role. However, for upcoming NASA
Artemis missions the active vehicle is both the chaser and target spacecraft. In addition,
both vehicles are cooperating with one another, sharing telemetry data, and relying on data
extracted from the GN&C system of the other. The process also includes a team of ground
support personnel in mission control are tracking and monitoring each spacecraft uplinking
state estimates and targeting solutions to support mission operations and enhance the onboard
flight system performance. Being able to quickly analyze the impact of both vehicles with
two different GN&C systems that also interact with the ground that does its own navigation
and targeting uploads is critical. This paper outlines how to perform this rapid analysis using
linear covariance techniques and applies them to a rendezvous scenario initiated in low lunar
orbit and completed in a Near Rectilinear Halo Orbit (NRHO) representative of the NASA
Artemis III mission.