Life Sciences in the Space Program 



placed within the centrifuge, space required by other research activities aboard 

 the spacecraft, and diameter limits below which problems associated with 

 coriolis forces (the result of an object's angular velocity within a centrifuge) and 

 gravity gradients become intolerable. 



Recommendation 



• A suite of variable-gravity facilities that include centrifuges of the following 

 designs should be available for gravitational biology research in space: 



— Small centrifuges that can be mounted in middeck lockers, Space- 

 lab/Space Station-style racks, free-flier satellites, or other targets of 

 opportunity for cell biology and small plant research 



— A 1.8-meter diameter centrifuge facility that can be rack-mounted in 

 Spacelab or aboard the Space Station at Initial Operating Configuration 

 (IOC) for rats, squirrel monkeys, and larger plants 



— A tethered (> 10-meter diameter) variable-gravity research facility for the 

 Space Station that would greatly reduce coriolis/gradient problems across 

 large animals and that would be operational before the start of any 

 human space missions of extended duration. 



Maximizing and Expanding Flight Opportunities 



Findings 



• Biological research requires the ability to repeat and/or modify procedures 

 based on the results of earlier experiments. 



• The lack of flight opportunities for life sciences researchers has numerous 

 unfortunate consequences, including the following: investigators become 

 increasingly discouraged as scheduled flights are repeatedly delayed; graduate 

 students, laboratory space, and institutional support become increasingly diffi- 

 cult to justify; and scientists who had been considering the submission of a 

 proposed experiment decide to pursue other objectives. 



Recommendation 



• Flight opportunities for life sciences experimenters should be expanded in 

 the following ways so that investigators can repeat or modify trials based on 

 the results of earlier experiments: 



— At least one locker on every Orbiter flight should be reserved and 

 dedicated to life sciences experiments. 



— One Spacelab mission dedicated to life sciences research should be 

 flown as frequently as possible. 



Autonomous life sciences free-flier satellites should be developed 

 capable of launch on either the Space Transportation System (STS) or an 

 expendable launch vehicle (ELV), STS recovery, or an autonomous soft 



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