Interactive method for planning fuel-efficient proximity operations using visual optimization aids

An interactive graphical system for planning fuel-efficient rendezvous trajectories in the multi-spacecraft environment of the Space Station, has been developed and experimentally evaluated. The method allows the astronaut to compose multiburn transfer trajectories between arbitrary initial chaser and target trajectories. The maneuvers, of which the available time span (window) is limited, are described in terms of the relative motion experienced in a Space Station centered coordinate system, and are subject to various operational constraints, such as departure-, arrival-, plume impingement- and spatial constraints. This paper specifically deals with the implementation and experimental evaluation of the visual optimization aids. The fuel optimization functions are based on classical orbital trajectory optimization techniques and are presented in the form of a “primer vector” diagram and a number of optimization pointers, which advice the astronaut whether and in which manner to modify trajectory waypoints for reducing the orbital maneuvering fuel use to a minimum. An extensive experimental program has been carried out to evaluate the effectiveness of the various visual optimization aids and levels of automatization. The results show that subjects, allowed to use the optimization aids, had a generally smaller planning activity, used on average about 10% less fuel, and were more consistent in their trajectory designs