Functional prioritization strategies and tradespace considerations for a self-reliant deep space habitat

Abstract

As human spaceflight missions extend further from Earth, reliance on ground becomes increasingly impractical due to communication delays with potential for occultations and the long transit time required for resupply. For these missions, incorporating autonomous capabilities into the habitat may offer enabling solutions to the challenges of deep space. Although it may be tempting to leverage autonomous systems wherever possible, the added complexity can also lead to new failure modes and/or schedule and budget overruns. Therefore, prioritizing those functions that are a) most critical to mission success and b) currently dependent on ground teams, can help to determine where emergent technologies offer the greatest potential return on investment toward self-reliant operations. This work presents a flexible, needs-based framework for prioritizing habitat functions according to their current Earth-reliance and criticality in order to assess where novel solutions may be most beneficial to enabling autonomous operations within the constraints of deep space. Proposed figures of merit for prioritizing spacecraft functions are defined, and can be used to directly compare technology solutions. Finally, a high-level demonstration is performed through a case study of the repair of the External Active Thermal Control System (EATCS) onboard the ISS in 2017. The evaluation framework and case study example presented here are intended to serve as a customizable template that can be adapted to mission-specific needs and constraints.