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Mission or Study ID:   EPSP
NASA Johnson Space Center (JSC)
Launch/Start Date:
Landing/End Date:
4 years, 9 months

The Extravehicular Activity (EVA) Physiology, Systems, and Performance (EPSP) Project sought to understand human performance during EVA with the aim of developing more safe and efficient systems for Exploration missions and the Constellation Program. This Project conducted a number of studies to understand medical safety and human performance issues related to working in partial-gravity environments.

The goals and objectives were to develop Exploration Mission EVA suit requirements which optimize human performance; to develop validated EVA prebreathe protocols that meet medical, vehicle, and habitat constraints while minimizing crew time and thus increasing EVA work efficiency; and to define acceptable Decompression Sickness (DCS) risks for exploration missions.

Multiple testing environments are necessary because no single Earth environment can perfectly simulate weightlessness or partial gravity. The project characterized human EVA performance and suit interactions in studies using several test beds, including the underwater NEEMO and Neutral Buoyancy Laboratory facilities, a lunar-simulated crater, and NASA's partial gravity simulators. By using these varied testing environments, NASA can gain a more complete understanding of human performance issues related to EVA and thus enable optimized EVA systems and suits in the future.

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