Summary 



Gravitational Biology 



Gravitational Biology studies the scope and operating mechanisms of one of the 

 strongest factors influencing life on Earth: gravity. It addresses fundamental 

 questions concerning how living organisms perceive gravity how gravity is 

 involved in determining developmental and physiological status, and how gravity 

 has affected evolutionary history. 



While these questions are motivated primarily by scientific interest, such research 

 can help determine if life can function effectively for extended periods in 



weightlessness or reduced 

 gravity as on the Moon or 

 Mars, or if artificial gravity is 

 required. Space-based research, 

 which requires variable-force 

 centrifuge facilities, provides 

 unparalleled opportunities to 

 expose organisms to fractional 

 gravity levels ranging from zero 

 to 1 g, and thereby to inves- 

 tigate the effects of gravity on 

 these organisms. 



Recommendations: In 



understanding the role of 

 gravity in the reproductive, 

 developmental, and metabolic 

 activities of all forms of life, 

 NASA should: 



Ground-based vestibular sled experiments at NASA's Johnson Spaa- Center test human 

 response to rectilinear acceleration. 



• Increase the number, duration, and regularity of life sciences experiments flown 

 in space. 



• Provide adequate inflight research capabilities, including a suite of variable-force 

 centrifuge facilities, on-orbit analytical equipment, and plant and animal vivaria 

 capable of supporting successive generations subjected to varying, controlled 

 gravity levels. 



• Coordinate Gravitational Biology research with that conducted by interrelated 

 science programs, such as CELSS and Space Biomedicine. 



• Operate its intramural and extramural research programs in a manner that 

 attracts and supports excellent new researchers, especiallv young scientists, ink) 

 the relatively new field of Gravitational Biology, as well as into other areas of 



space lite sciences. 



Planetary Biosciences Research 



[Tie Biospherics Research Program studies the biological processes that have 

 shaped the chemical history of Earth. Human activities, such as fossil fuel 



