Continuous metabolic and cardiovascular measurements on a monkey subject during a simulated 6-day Spacelab mission

In May 1977 the NASA Ames Research Center and NASA Johnson Space Center jointly conducted a test of the feasibility of performing various types of biological and medical experiments during future Spacelab flight missions. One of the experiments was designed to examine the effects of weightlessness on several basic parameters of metabolic and cardiovascular function in an adult nonhuman primate. The subject animal, a 10 kg male pig-tailed monkey (Macaca nemestrina), was prepared 3 months before the test with a surgically implanted NASA/Ames biotelemetry unit to provide continuous measurements of body temperature and selected cardiovascular parameters. Three days before the simulated "launch" the animal was inserted into a fiberglass pod system to provide continuous measurement of respiratory gas exchange. The pod system was installed in a Spacelab mock-up and all physiological data channels were recorded continuously for 2.6 days prior to "launch", for 6.3 days during "flight", and for 1.8 days after "landing". The experiment was tended entirely by the Spacelab flight crew during the "flight" period. Statistically significant diurnal variation was noted in oxygen consumption and carbon dioxide production rates, body temperature and heart rate, but not in respiratory quotient or blood pressure. A transient increase of the parametric values was noted during the latter portion of the "flight" period, possibly occasioned by increased flight crew activity. The high quality of the continuous data obtained during the 10.7-day total experiment period demonstrates the feasibility of performing sound physiological experimentation on nonhuman primates in the Spacelab environment.