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An EVA simulation with a medical contingency scenario was conducted in 2006 with the NASA Haughton-Mars and EVA Physiology System and Performance Projects, to develop medical contingency management and evacuation techniques for planetary surface exploration. A rescue/evacuation system to allow two rescuer astronauts to evacuate one incapacitated astronaut was evaluated. The rescue system was utilized effectively to extract an injured astronaut up a slope of15-25° and into a surface mobility rover for transport to a simulated habitat for advanced medical care. Further research is recommended to evaluate the effects of reduced gravity and to develop synergies with other surface systems for carrying out the contingency procedures.

Computer simulation of extravehicular activity (EVA) is increasingly being used in planning and training for EVA. A space suit model is an important, but often overlooked, component of an EVA simulation. Because of the inherent difficulties in collecting angle and torque data for space suit joints in realistic conditions, little data exists on the torques that a space suit’s wearer must provide in order to move in the space suit. A joint angle and torque database was compiled on the Extravehicular Maneuvering Unit (EMU), with a novel measurement technique that used both human test subjects and an instrumented robot. Using data collected in the experiment, a hysteresis modeling technique was used to predict EMU joint torques from joint angular positions. The hysteresis model was then applied to EVA operations by mapping out the reach and work envelopes for the EMU.

Previous studies have shown that a multi-axis ankle joint accommodating abduction and adduction as well as ankle flexion/extension and rotation could be practically incorporated into a pressure suit. Several candidate configurations were manufactured and the performance of the enhanced ankle joints evaluated. Experience has suggested that these enhancements could be of significant benefit for planetary exploration missions requiring extensive walking over uneven terrain. During 1999, prototype pressure suit boots incorporating a multi-axis ankle joint configuration were manufactured. Their effect on balance stability and locomotion capabilities across slopes and over uneven surfaces in a pressurized spacesuit were evaluated in a series of 1-g experiments. This paper describes the enhanced test boots, the test procedure, and the results. Design refinements and further testing are recommended.

Micrometeoroid and orbital debris (MMOD) penetration hazards have been a concern for the large number of EVA’s (Extravehicular Activities) expected during the assembly and operation of the International Space Station (ISS). Earlier studies have shown large uncertainties in estimated spacesuit penetration risks. This paper reports the results of recent tests and analyses that have significantly expanded the Shuttle EMU (Extravehicular Mobility Unit) hypervelocity penetration database and clarified our understanding of the associated risks. The results of testing have been used to develop improved estimates of the cumulative risk of penetration during EVA's through the first ten years after the beginning of ISS construction. These analyses have shown that the risks of MMOD penetration during EVA will be somewhat less than the risk of a critical penetration of the ISS itself over the same ten-year period.

A cooperative program undertaken by Zvezda and Hamilton Standard to address the required walking mobility for future planetary missions has focussed on space suit foot and ankle mobility. It has included the evaluation of the performance of a boot sole metatarsal (toe) joint and two different ankle joint configurations. A field test with a highly mobile space suit prototype by NASA provides data that complement the results of the above study. Experience in traversing a variety of terrain similar to that expected on Mars provides confirmation of the value of pressure suit ankle and boot sole mobility in the field. Taken together, these studies provide useful data for the design of future planetary exploration spacesuits. Laboratory and field test results are presented and some of their implications for planetary space suit designs are discussed.