Dressed for Success: Eva System Competancy and Containment for Science Capabilities and Contamination

Introduction: The key to significant lunar science and exploration return lies in supplying the crews on the surface with a robust EVA capability. This capability should include high mobility pressure garments; tactile, dexterous gloves; reduced overhead in preparing for and recovering from EVAs; management of regolith contamination; and control of suit leakage to prevent planetary contamination. Building on the legacy from Apollo, Shuttle and ISS, the present complement of prototype surface suits have made good progress toward achieving these goals for the future lunar surface suit system. The next step is to translate the lessons learned from these systems into requirements for the next generation surface EVA system. Apollo Legacy: The Apollo space suit was a departure from the previous tradition of providing astronauts with pressure garments that were to be used in emergency cabin depressurization. Emergency suits should be reasonably comfortable when unpressurized, and provide a safe environment for the (assumed) limited period of time when they were needed during an in-flight emergency. In contrast, the Apollo space suit provided the crew with reasonable comfort and mobility , including pressurized operations for up to 8 hours at a time on the lunar surface. In addition, the pressure garment needed to provide a host of other nominal and emergency capabilities, including performing as a comfortable prebreathe " container " for pre-launch pure O 2 prebreathe; protect the crew during the launch to orbit acceleration of up to 4.5 g; act as a survival suit in case of launch abort into the Atlantic Ocean; provide contingency spacewalking capability to transfer the crew from the Lunar Module (LM) to the Command Module (CM) in lunar orbit in the event of an internal hatch failure; and provide up to 104 hours of unpressurized survival in the event both the LM and the CM could not be repressurized after the lunar surface mission. The two Apollo suit models, the A7L and the A7LB, fulfilled each of these tasks admirably – 12 lunar surface crews completed over 160 man-hours of lunar surface EVA between 1969 and 1972. However, the A7L series had some deficiencies in mobility that taxed each of the crews that wore them. The most significant of these deficiencies was glove mobility – the gloves proved to be very stiff, with limited tactility and dexterity, and resulted in substantial forearm and hand fatigue and finger damage. The pressure garment, as well, had deficiencies …