Biosatellite 3: a physiological interpretation

On 28 June 1969, a macaque monkey was boosted into orbit for a projected 30-day flight. It was aborted after 8 1/2 days and the monkey died 16 hours later. Data collected indicate: Weightlessness and the hypothermia acted to shift blood volume centrally; this provided a strong drive for the reduction of blood volume. Restraint, unusual vestibular sensations, and the continuing polydipsia all acted to disturb the central mechanisms affecting salt and water metabolism; it is probable that the function of the kidney was significantly affected and that an excessive amount of salt was lost. We can speculate that a serious electrolyte disturbance was superimposed on growing dehydration. Unpleasant vestibular sensations may have contributed to the high evaporative loss by autonomic disturbance, the whole problem being compounded and reinforced by the unnatural restraint to which the monkey was subjected.