PRINCIPAL INVESTIGATOR (S ): G. Donald Whedon, Leo Lutwak, Paul C. Rambaut , 



Michael W. Whittle, Malcolm C. Smith, Jeanne Reid, 

 Carolyn S. Leach, Connie R. Stadler, and Deanna D. 

 Sanford 



EXPERIMENT TITLE/NUMBER : Mineral and Nitrogen Metabolic Studies, M071 



PROGRAM/MISSION : Skylab 2, 3, 4 



CLASSIFICATION : Human 



DISCIPLINE(S) : Musculoskeletal 



OBJECTIVES : To determine major changes in the chemical state of the muscular 

 and skeletal systems under space flight conditions. 



PROTOCOL : The study required constant dietary intake, continuous 24-hour 

 urine and total fecal collection for 21 to 31 days preflight, inflight, and 

 through R+17-18. 



EQUIPMENT : Urine measurement and collection system, fecal collection system, 

 Specimen Mass Measurement Device (SMMD). 



RESULTS : The average 24-hour urinary creatinine excretion was not changed by 

 space flight. Increases in urinary calcium were similar to those in bedrest 

 studies. Increased excretion of nitrogen and phosphorus reflected substantial 

 loss of muscle tissue. Both muscle and mineral loss occurred despite an 

 exercise regimen on all flights. 



CONCLUSIONS : Unless protective measures can be developed, capable musculo- 

 skeletal function is likely to be impaired in space flights ultimately to be 

 conducted to Mars, of one and one-half to three years duration. 



PUBLICATIONS : 561, 563, 564, 565, 566, 567, 568 



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