ORBIT: Orbital Repairs By Innovative Technology


The University of Maryland’s Space Systems Laboratory has a long history with multiple design projects for small single-person spacecraft (SPS) intended for extravehicular operations. Since the SPS concept has been criticized as differing from teleoperators, suited-missions, and other space utility vehicle (SUV) models only by the ability of the operator to have direct vision (“eyes-on”) of the worksite, “hands-on” interaction with the worksite, and simultaneous use of robotic arms. Testing will focus on identifying performance differences between the methods. To quantify effectiveness for each option, we performed a Fitts’ Law tapping task in three hands-on environments: shirt-sleeve, space-suit arms, and SPS suit-arms, as well as two robotic control environments: one with direct eyes-on vision, and one using video screens for teleoperation. After each series of tasks, participants completed a short survey including the NASA Task Load Index (TLX) as well as a Cooper Harper rating. We hypothesized that a combination of hands-on control and eyes-on robotic control will be the most suitable design for an SUV. Experimentally, we found that within the hands-on control environments (shirt-sleeve, suit arms, SPS arms), there is not much variation in task difficulty, but that these environments were much easier to control than the robotic control environments. Among the robotic control environments, subjects performed better overall when using direct eyes-on vision, as opposed to teleoperation. Our findings suggest that combining eyes-on and hands-on interaction is both important and significant in SPS design and handleability.