Development of a ground test & analysis protocol for NASA's NextSTEP phase 2 habitation concepts

The NASA Next Space Technologies for Exploration Partnerships (NextSTEP) program is a public-private partnership model that seeks commercial development of deep space exploration capabilities to support human spaceflight missions around and beyond cislunar space. NASA research engineers and subject matter experts have been tasked with developing the ground test protocol that will serve as the primary means by which these Phase 2 prototypes will be systematically evaluated. The purpose of a common ground test protocol for the Phase 2 Habitation Concepts is to consistently evaluate different commercial partner ground prototypes to provide data-driven, actionable recommendations for Phase 3. This paper describes the process by which the ground test protocol was developed and the objectives, methods, and metrics by which the NextSTEP Phase 2 Habitation Concepts will be assessed. Ground test evaluations will include human-in-the-loop (HITL) habitation tests, subsystem standalone tests, analyses, and inspections. HITL testing will involve crews of four astronauts conducting multiday mission timelines that integrate all habitation operations (e.g., eating, sleeping, waste collection system operations, exercise), representative science and robotics tasks (e.g., low-latency teleoperations rover operations, sample return, life science, medical evaluations), and extravehicular activity (EVA), (e.g., airlock configuration, pre/post operations). Established subjective and objective metrics will be collected and analyzed to provide the data and actionable recommendations for Phase 3 of the NextSTEP program. This paper begins with a summary of NASA's deep space habitation plans, the goals of the NASA NextSTEP activity, and the process by which the ground test objectives were derived. It then details the strategic questions and hypotheses, and describes the inspections, analyses, subsystem standalone tests, and HITL integrated tests that will be used to address the functional requirements and ground test objectives. Data collected from these assessments will be analyzed to determine the acceptability of habitation element configurations and the combinations of capabilities that will result in the best habitation platform to be recommended by the test team for Phase 3.