The Biochemical, Physiological, and Metabolic Effects of APOLLO Nominal Mission and Contingency Diets on Human Subjects While on a Simulated APOLLO Mission

摘要

Four human male subjects participated in a 90-day experiment consisting of 60-day and 30-day confinement periods with a 5-day break between. The subjects were confined either to the controlled activity facility of the chamber of the Life Support Systems Evaluator at altitude wearing pressure suits unpressurized and pressurized at 3.7 psi. The subjects ate a fresh food diet, an Apollo nominal mission diet, or an Apollo contingency diet that provided 2200, 2500, and 900 kcal/day, respectively. The rod form of the contingency diet was the most acceptable from an organoleptic standpoint. The tube form was more easily handled from a functional standpoint, although the formulation of the tube food as well as the tube itself needs to be improved to make it operationally more effective than at present. The subjects lost about 500 g/day of body weight while on the contingency diet of which about 50% is estimated to be water. About 40 g/day of body weight was lost because of protein catabolism. Blood levels of sodium, potassium, phosphorus, chloride, calcium, and magnesium were maintained in the normal range of clinical values. Physiologic measurements all were in the normal range of clinical values. However, the 17-hydroxycorticoids of the urine decreased to low normal and below normal ranges of clinical values. Three of the four subjects completed a simulated Apollo emergency mission wearing a pressure suit pressurized at 3.7 psi and on a 900-calorie contingency diet. There were no adverse effects upon their health and no evidence that their capacity to function in a normal manner was in any way impaired. (Author)