W.W. Hastings Indian Hospital
Tahlequah, OK 74464
It has been many years since man first set foot on the moon. The next logical step in the sequence exploration is a manned mission to Mars. Although the Martian surface has been explored by unmanned spacecraft, human interplanetary travel presents some unusual difficulties, the most salient of which is the lack of gravity. In a zero-gravity situation the human body is not able to maintain bone mass resulting in a type of osteoporosis. It is estimated that a human being loses approximately 1% of bone mass for each month in space. A typical Mars mission of thirty months could therefore result in 30% bone loss, which is considered severe osteoporosis. This could result in a high-risk of fracture upon return to EarthÕs gravitational field. This is considered one of the major showstoppers of long duration space flight. Various protocols have been developed in an attempt to minimize the bone loss in zero-gravity. These include vigorous exercise programs, which may last several hours each day, and weightlifting using elastic cords as a substitute for weights. There is some evidence that these measures may compensate for lack of gravity and reduce the severity of the bone loss. Loss of bone mass from the long bones of the skeleton may not be the only problem. Recent research in periodontology has shown that osteoporotic periodontal bone is more susceptible to breakdown than healthy bone, and that tooth loss is more frequent in subjects with osteoporosis. The strategies which may prove useful in the long bones, exercise, etc., are not adaptable to the oral bone. The bone surrounding the teeth is very susceptible to damage from the type of overloading that this would cause. Strategies to preserve the oral bone may include dietary and pharmacologic measures, as well as artificial gravity.