Guidance Strategy for Hyperbolic Rendezvous

In cycler and semi-cycler Mars mission architectures a crew “taxi” docks with the interplanetary transfer vehicle on a hyperbolic flyby trajectory, hence the term “hyperbolic rendezvous.” An algorithm that guides the taxi to intercept the transfer vehicle is presented with a control law for final approach. When navigation and thrust uncertainties are included, the vehicles dock at a closing rate of a few cm/s with a misalignment of a few cm. Because this maneuver is critical to crew survival, we advocate redundant systems and propellant margin for 3-σ (~99.7%) reliability. These safety measures lead to marginal increases in taxi mass.