At present our planet has an orbiting space station, in which people have been living, sometimes continuously for many months. They have, of course, been tested, to see what the effects of living in micro-gravity are. Here are some of the results:
Space affects the body in many ways. One measurable effect is gradual bone loss ? at a rate of 1 to 1.5% every month. The long term effect of this is similar to osteoporosis, or brittle bones.
Increased risk of kidney stones, which is linked to the slow demineralization of the bones, and also loss of muscle mass. As the muscles shrink, the general strength and endurance of the body drops, so astronauts may become enfeebled.
Because the heart is not working against normal gravity, it too can become weaker, and suffer from rhythm disturbances. Because the internal pressures of the body have altered, more fluid is pushed into the head, and less down to the feet and hands.
Because living in space alters the normal circadian cycle, (clearly defined day and night) astronauts can suffer from stress, and loss of sleep, which leads to a lowering of their immunity from infections.
Astronauts also need . . .