On the 20th anniversary of the first manned lunar mission in July, President Bush called for a permanent return to the moon and a manned Mars expedition. While some critics quickly labeled the proposal as political pie in the sky, life scientists had more down-to-earth concerns.
They pointed out that, although a Mars mission could last as long as three years, three months is the longest any United States astronaut has been in space. And while a moon base could mean years of low gravity for its inhabitants, the current record is less than eight months, set by three Soviet cosmonauts in 1984.
“Before we subscribe to such a proposal, we need to know how long we can keep a man in space,” says Rufus Hessberg, executive vice president of the Aerospace Medical Association. “Our knowledge today is meager; what we’ve found so far is mostly that we need more ...
