Telerobotic Ground Control of a Free-Flying Space Camera

Abstract

NASA has developed a free-flying camera known as AERCam to assist Space Shuttle and Space Station operations. The first AERCam vehicle was controlled from within the Space Shuttle using a hand-held controller. We have developed a system for controlling AERCam remotely from the ground, which involves significant communication delays. We have tested its use with NASA's AERCam dynamics simulation in place of the actual vehicle. Our ground system uses a predictive display1 that is based on a similar simulation of Shuttle and AERCam dynamics. For both physical and numeric reasons, the behavior of the remote vehicle may drift from what is expected by the predictive display system. We have developed a mechanism to periodically re-establish correspondence of the ground simulation with the remote vehicle using tracking data that reports AERCam's recent behavior. Our system also provides a basis for future development of more advanced autonomous ground control for space vehicles such as AERCam.