Flight Programs 



investigations deal with complex and incompletely understood interactions, 

 repetitive and rapidly executed variations of experiments and a large statistical base 

 are essential for understanding basic life processes. Moreover, investigators are 

 needed to monitor experiments conducted in a space laboratory and to analyze 

 research results. 



Long-duration human missions pose considerable challenges for life scientists. The 

 times required for round-trip journeys to other planets are measured in years. 

 Since no analog on Earth duplicates the environment of space, the investigation of 

 long-term human tolerance to space flight requires the use of facilities such as the 

 Space Station. Tests of human competence to withstand years of space travel must 

 be initiated and validated long before human interplanetary missions are launched. 

 Not to do so would risk significant delays or even cancellation of such missions. 



Findings 



• The effects of zero or partial gravity on humans and other forms of life are not 

 fully understood. 



• The radiation environment in space, particularly galactic radiation, is not fully 

 understood. 



— Standards for exposure to galactic radiation have not been established with 

 any degree of confidence. 



— Research into the effects of radiation exposure in space will necessitate 

 orbital inclinations and periods that are often unobtainable or impractical 

 with the STS. 



• Current mission planning requires extended human space flight. American 

 space-flight experience is limited to 84 days. While the Soviet Union has 

 collected data on one individual from a 326-day flight, its information on 

 human space flight exceeds ours only with regard to cumulative number of 

 days spent in space. The Soviet data are mostly of an observational or 

 operational nature. Extended-duration missions, such as the exploration of 

 Mars, will require stay times of a year or more. 



— Available life sciences data are insufficient to support the design of a 

 system that would use centrifugal force as a long-term substitute for gravity. 



— In addition, data are insufficient and incomplete to support the use of 

 proposed countermeasures to alleviate problems associated with long- 

 duration space missions. 



• Research has to be expanded to understand the reaction of living organisms to 

 the space environment. 



— While mission planning will revolve around the specific physiology of 

 humans, substantial amounts of applicable data can be derived from 

 experiments on nonhuman subjects. 



— A vigorous program of animal research is vital to extrapolate the effects of 



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