As a solution to the many problems that come from weightlessness, many scientists are pinning their hopes on artificial gravity -- creating systems that mimic the gravitational pull of our own planet--for the long journey to Mars.
The idea is not new. Tilting wheel type amusement park rides use the same principle, spinning to keep riders safely pressed to the side of the wheel as it turns, to a vertical position. Already in the early 1950s, Wernher von Braun, one of the architects of the Space Age, imagined solving the problems of weightlessness with the same idea -- a tremendous, wheel-shaped space station that would create its own gravity by spinning once every twenty-two seconds.
Such a structure would not be able to travel to Mars, but it did suggest futuristic designs for a ship that could. One idea on the drawing boards is to connect three separate ships in a circle like children in a game of ring-around-the-rosy. Another plan would leash two capsules together with a strong Kevlar tether, then rotate around one another like a pinwheel.
On paper, such designs seem possible; at least they don't defy the known laws of physics. But the cost of actually realizing them could be enormous, and even if they could be translated into real ships, some scientists think that such craft might be more troublesome than helpful. They might aggravate inner-ear problems or cause greater space sickness. And which gravity should the ship mimic, Earth's or Mars's or something in between?
The complexity of the ships raises other serious concerns. What if the system breaks down twenty million miles into the trip? Like many other issues and ideas regarding a journey to Mars, artificial gravity is still only in its early stages and requires much more thought and research.
