Life Sciences in the Space Progtum 



The design of EVA systems should begin with an analysis of the requirements for 

 conducting the EVA tasks. Recognizing the problems and accepting the risks 

 involved in EVA operations is critical to such an approach. The need is for a high 

 capability svstem, which has the potential to encourage growth in satellite- 

 servicing operations and other EVA activities associated with the Space Station. 

 Use has been made of an anthropomorphic suit for zero-gravity activity. An EVA 

 enclosure concept, sometimes called a "man in a can," may, however, be more 

 effective for most situations. An atmospheric pressure room inside the enclosure 

 would allow for a variety of behaviors (e.g., earing, resting, scratching), and use of 

 an integrated locomotion system could greatly reduce physical exertion and 

 lengthen EVA time. For tasks requiring dexterity, a number of end effectors must 

 be developed; prehensors and gloves should be tailored to the jobs to be done. 



EVA systems for surface use will present different challenges. They must allow 

 mobility in 1/6 or 1/3 gravity, withstand the wear from surface dust and chemicals 

 over 1 to several months, withstand and function in a high CO ; atmosphere 

 (Mars), and be light enough to be worn and carried by an astronaut under the 

 prevailing gravity conditions for full work days. The weight of the portable life 

 support system (backpack) must be addressed. Provisions must also be made for 

 backpack regeneration and suit servicing on the surface of another planet. 



At present, no one group within NASA is evaluating the entire question of EVA. 

 A comprehensive look at the direction of EVA operations is clearly needed to 

 identify the requirements of future activities and to develop EVA systems capable 

 of satisfying these requirements. 



Habitability Requirements 



Habitability involves the design of environments to support and enhance crew 

 productivity, performance, health, safety, and comfort (4,5). Early research in 

 habitability focused on such factors in space flight as temperature and humiditv, 

 sensory deprivation, and variable acceleration (6). Current studies of spacecraft 

 habitability emphasize the relationship between technological and human factors 

 (7). The extent to which environments are congruent with the needs and 

 preferences of the individual determines the degree of person-environment fit, or 

 habitability. The following list identifies the major spacecraft factors pertinent to 

 habitability and the well-being of the crew: 



Volume 



Temperature and humidity 



Lighting 



Yibroacoustics 



Personal hygiene and waste management 



Privacy 



Aesthetics or functional decors 



Food systems 



Leisure and recreation 



Environmental monitoring and control. 



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