A LOOK TOWARD THE FUTUREIf permanently occupied space stations are developed in the future, as planned, workers in space
medicine will focus increased attention on the most crucial health issues involved in long-term spaceflight: bone decalcification, changes in the immune system, heart and muscle deterioration, and long-term exposure to radiation. Animal experiments and studies of drug effectiveness in space will form an important part of such
research.If manned interplanetary flight becomes a priority in the farther future, health
problems relating to the colonization of the Moon and the exploration of Mars will undoubtedly play a larger part in future space-medicine programs. Research on these problems will include the development of crew selection criteria for flights of very long duration, and the maintenance of mental acuity and physical well-being during such prolonged periods of relative sensory deprivation. Maintaining the social health of small-scale societies on space stations and severely isolated extraterrestrial outposts will also present unique challenges.