Investigations of rhythmic phenomena of various physiological systems can result in knowledge of the utmost importance to medicine. Rhythmic phenomena are found in the cardiovascular system of normal humans. Changes in these rhythms have the potential of foretelling abnormalities (heart disease, arteriosclerosis) before outward signs are manifested, allowing for earlier diagnosis, treatment, and control or cure. The spacecraft sterilization program requires the use of rooms having the lowest attainable level of bacterial contamination. The rate of dissemination of bacteria from the humans in the room is basic to the problem. Data on this matter are being obtained through support of the Communicable Disease Center of the U.S. Public Health Service. The findings are affecting the measures used in surgical practice to lower infection rates. Studies on the physiology of hibernation in mammals are important to understand temperature regulation and the mechanism of survival at low body temperatures. The purpose of this type of research is to understand and use reduced metabolic activity in astronauts on future extended space flight. Other applications involve studies of the mechanisms of injury and freezing biological organisms, for improving techniques in hypothermic surgery, pathology, and preservation of tissue for human grafting. Food and Agriculture Gathering agricultural information by remote sensing of Earth’s surface from aircraft, balloons, and satellites has a potential application in research and development. Current needs for data gathered in this way include crop and livestock surveys for marketing planning; soil mapping; crop disease, insect, and weed surveys; soil conservation management and research; and crop acreage control programs. As population and world trade increase, the needs will become even more intense for regularly scheduled synoptic surveys of the world’s agricultural lands for crop plantings and harvests; determining the condition of crops as affected by drought, disease, or insect outbreaks; and studies of the lands suitable for agricultural development in underdeveloped countries. The only way that worldwide synoptic surveys can be made is by using orbiting platforms. The NASA nutrition program for developing diets for prolonged manned and animal space flight lends itself to civil defense purposes; military maneuvers where space and weight are prime considerations; polar and desert exploration; reducing hunger in underdeveloped countries; and detecting metabolic diseases as well as diseases of infancy and old age. For space research such a diet can be used on prolonged manned space flights, animal experiments in space, manned orbiting laboratories, and space and planetary stations. Studies on the packaging and stability of foods under various conditions of humidity, temperature, and radiation will lead to better processing and storage.