Handling Qualities Evaluation for Spacecraft Docking in Low Earth Orbit

Abstract

A new generation of spacecraft is now under development by NASA to replace the Space Shuttle and return astronauts to the Moon. These spacecraft will have a manual control capability for several mission tasks, and the ease and precision with which pilots can execute these tasks will have an important effect on mission risk and training costs. A simulation evaluated the handling qualities of a generic space vehicle based on dynamics similar to one of these spacecraft, NASA’s Crew Exploration Vehicle, during the last segment of the docking task with a space station. This handling qualities evaluation looked at four different translational control systems, two of which are available in current space vehicles and two of which were adapted from aeronautical vehicle control system designs. These response types were flown with three levels of translation-into-rotation dynamic coupling arising from a longitudinal offset between the reaction control system thrusters and the vehicle’s center of mass. The effect of variations in jet thrust was also measured for a single response type. The results indicate that greater translation-into-rotation coupling is strongly correlated with degraded handling qualities, but that different response types do not have a major effect on pilot workload, final docking performance, or overall handling qualities.