Concept Evaluation of Minimal In-Space Vehicles in Support of Exploration External Operations

Experience gained with International Space Station has demonstrated the need for both planned and contingency external operations to maintain system functions. As the focus shifts to operations beyond low Earth orbit such as the Deep Space Gateway and eventually Mars transit vehicles, the need for external operations will not decrease, but the remoteness, communications limitations, and implications of an EVA accident will change the approach taken. One factor would be the proposed space exploration vehicle (SEV), currently envisioned as a two-person vehicle capable of supporting EVA via suitports and designed for extended duration sorties. However, the current SEV concepts are spacecraft of a scale comparable in mass to Dragon or Starliner vehicles, and therefore unlikely to be affordable in a cost- and mass-constrained exploration architecture. In addition to a simple mass-based cost estimate, some of the more recognizable features of the current concepts, such as multiple large windows, will further amplify the development and production costs of the system. As an outgrowth of ongoing research into single-person space utility vehicles, the University of Maryland has performed a number of studies of the potential roles of small vehicles to support external operations in microgravity. In this paper, we consider how direct ``eyes-on'' vision compares to various forms of video in the control of dexterous robotics. Tests to date have demonstrated that direct vision is generally inferior to multiple high-resolution video views, calling into question the need for large and/or multiple windows.