For the Truly Discerning Traveler: A 10-day Jaunt in Space
Micro-gravity affects the body in several ways, says Borer. "First there are muscular changes that can cause atrophy of skeletal muscles," he says. Halvorson says that "everyone gets bird legs, you know, skinny legs." Because the legs don't have to deal with the force of gravity, they have no work to do, says Borer. No work means that muscles can waste away. "The countermeasure to this is intensive exercise during part of every day," says Borer.
At the same time, micro-gravity causes bones to lose calcium and become fragile, says Borer. The bones lose so much calcium that the amount of calcium circulating in the blood increases, he says. Unfortunately some of this calcium finds its way to the kidneys where it can form kidney stones. "There is an increased risk for kidney stones with extended time in space," says Borer.
Probably the most unpleasant aspect of space travel for the space tourist would be space sickness, a type of nausea that is very similar to other types of motion sickness, says Borer. He says that this usually passes in a day or two.
Considering these problems, space travel is definitely no Love Boat cruise, but Borer says that extended space travel may pose even greater risks. For example, he says there are some indications that extended time in space may have an effect on each of the major organ systems. In the case of the heart -- Borer is a heart specialist -- some researchers think there could be some structural changes if one lived for years in a micro-gravity environment.
Petranek says that any potential physical side effects can probably be overcome. The biggest risk, he says, is to the space travelers' mental health. He says that packing seven or more people in a vehicle that is the size of a family minivan and sending them off to Mars -- a trip that could take nine months each way -- is probably a recipe for mayhem. Humans, he says, have a long track record of mental breakdown when exposed to long periods of isolation or confinement.
He is so convinced of the risk that he devoted the cover of his May issue to an article titled, "Can we get to Mars without going crazy?" Petranek says he has real doubts that the mental health hurdles can be overcome. One approach that is being tried, he says, is a computer program dubbed "therapist in a box" -- interactive programs that are designed to assess a space traveler's mental and emotional state.
To sum up then: A space vacation can leave the traveler with weak muscles, fragile bones, queasy stomach, and a strong likelihood that one is "the weakest link."
And that's not all. This fun vacation is likely to cost much more than four years at an Ivy League college or 10 years jet-setting around Europe. Do the math, says Halvorson: "Each launch of the space shuttle costs $350 to $400 million." Petranek says it costs "$10,000 for every pound you put in orbit," so even a svelte 105-pound adult is looking at a ticket price of more than $1 million, while a 350-pound NFL lineman would pay $3.5 million for a ticket to spend Super Bowl Sunday in space.