Weightlessness & More......Learning How to Survive in Space!
When John Glenn returned to space, he was at age 77 the oldest person to contend with weightlessness.
Weightlessness is the state of gravitational forces toward zero gravity. With zero gravity, the force of the pull of the earth on the body is equal to the force pulling the body away from the earth. Space crews now and space travelers in the future will be exposed to the short- and long-term effects of this phenomenon.
With weightlessness, there are multiple effects, including:
From long space flights, we have learned that the body in space needs a little over a month to get used (acclimated) to these changes. Intermittent physical exercise can markedly improve the situation.
Once back on earth, the majority of these changes vanish and most
matters revert to normal But there is nonetheless an initial period
of weakness and difficulty with balance back on earth that may last