The next small step
The microgravity experienced in space missions has serious effects on human physiology. Kevin Fong looks at the effects of prolonged weightlessness on the human body and our current understanding of the effects of microgravity on physiology
Astrodynamic considerations and existing propulsion technology limit the speed with which a crew can be delivered to and returned from the surface of Mars. A typical energy efficient mission profile might involve six months of outward bound journey, up to a year and a half of exploration on the planets surface, and a return flight lasting another six months.1 This comes to nearly a thousand days, more than twice the length of any single mission in the history of human space flight and an order of magnitude longer than routine International Space Station operations.
Several hazards await the crews of missions to Mars, including radiation exposure and the psychological stress of spending 30 months in a confined habitat, further from Earth than any human in history, with death no more than a hulls thickness away.
Prolonged exposure to microgravity seems to affect almost all physiological systems. Disturbances of haemopoiesis, immunosuppression,