Feasibility of MCP and Hybrid GP/MCP Architectures for Martian EVA: A Trade Study Perspective

To meet the intensive extravehicular activity (EVA) schedules proposed for Martian surface exploration, EVA suits will need to be lighter, safer, and more mobile. Current gas pressure (GP) space suits are excessively heavy, lack mobility and dexterity, subject astronauts to a high rate of injury due to stiffness and fit, and possess inadequate durability. These limitations necessitate the investigation of solutions to enable future astronauts to explore the Martian environment safely and effectively. Several suit architectures have been proposed utilising (at least in part) mechanical counter pressure (MCP). This is the application of pressure directly to the body, typically using a skin-tight, elastic garment. Considerable research effort has been put into the concept of a full MCP suit and numerous proposals for hybrid suits have been made. These hybrid suits incorporate a combination of GP and MCP in different configurations (layered and segmented). In this perspective piece we explored both MCP (full and augmented) and GP-MCP hybrid architectures as alternatives to full GP suits to determine the most promising pressure garment architecture that best serves Martian EVA requirements. The MCP and GP-MCP hybrid architectures were assessed by trade study for their suitability to meet Martian EVA requirements (custom capability scale) and to evaluate their maturity using NASA’s TRL system. Overall feasibility was defined as the product of normalized capability and maturity scores. Architectures that failed to meet minimum requirements were ruled out. Results indicated GP suits are the most mature technology (TRL), while augmented MCP and 60% segmented hybrid architectures are best suited to meet Martian EVA capabilities (capability assessment). Overall, we suggest the augmented MCP and 60% segmented hybrids are the most feasible architectures for effective Martian EVA.