Six Degree ... Of-freedom Sim1jlation of a Manned Orbital Docking

This paper describes an analog computer simulation of a manned orbital docking system conducted as a fe~sibility study. In addition to determining the possibility of a human operator performing guidance and attitude control functions with a minimum amount of displayed information, additional purposes of the study were to determine (1) terminal values of range rate, line-of-sight (LOS) angle, LOS rate, lateral miss, relative attitude angle, and fuel consumption, (2) pilot procedures and capabilities and, (3) minimum display requirements. The orbital docking system studied consisted of an orbiting Earth satellite (target vehicle) and a manned astrovehicle (chaser vehicle). The target vehicle was assumed to be attitudestabilized in a circular orbit so that the longitudinal (roll) axis was coincident with the orbital velocity vector. Initially, the chaser vehicle was plaeed ahead of the target in a nearby orbit with a fixed closing· velocity relative to the target. Using a periscope view of the target plus radar-derived range and range rate information, the pilot's task was to guide the chaser vehicle toward the target such as to satisfy prescribed terminal conditions. In particular, he. was required (i) to maneuver his vehicle into the orbit plane of the target, (ii) to align his roll axis with that of the target, (iii) to establish a specified roll attitude relative to the