Back To Earth

By MICHAEL D. LEMONICK

"I feel fine," said a smiling Yuri Romanenko in Moscow last week. It was the Soviet cosmonaut's first public appearance since his record-breaking 326-day sojourn in space, and what he had to report was dramatic: he had suffered virtually no ill effects from his prolonged flight. In the past, Soviet cosmonauts have returned from long missions with bones, muscles and cardiovascular systems weakened by extended periods in zero gravity. But Romanenko claimed he could stand up, albeit shakily, shortly after his Soyuz capsule touched down in Soviet Kazakhstan on Dec. 29. Said he: "My muscles were strong enough to support me. As far as heart palpitations, sweating, that sort of thing -- I didn't feel anything of that sort. In fact, one day after returning to earth, I went for my first jog, for about 100 meters."

His remarkable recovery was a triumph for the Soviet space program. One concern that has clouded plans for a manned mission to Mars is the fear that cosmonauts' health would deteriorate badly in the extended weightlessness of the 30-month round-trip voyage. "Now," says Cosmonaut Training Commander Vladimir Shatalov, "we are sure that it is possible to complete such a mission."

Some U.S. experts believe such confidence is premature, yet they are following the Soviets' progress with interest. Only five years ago, two cosmonauts returned from 211 days in space suffering from dizziness, high pulse rates and heart palpitations. They were unable to walk for a week, and a month later they were still undergoing therapy to strengthen atrophied muscles and weakened hearts. Without gravity to work against, muscles -- including the heart muscle -- begin to waste away, and calcium, for reasons that are poorly understood, leaches out of the bones.

The obvious solution was a regular exercise regimen. After a few false starts, the Soviets seem to have found an effective in-flight training program. Cosmonauts now spend their waking hours in a "penguin suit," a running suit laced with elastic cords that creates resistance -- and needed exertion -- with nearly every move they make. They also go through extensive workouts that include two-mile runs on a treadmill. Throughout their missions cosmonauts stay on a diet designed to keep physical deterioration to a minimum. Romanenko's doctors say he lost at most 5% of his bone calcium, while other cosmonauts, although weightless for shorter periods, have suffered far higher losses. The cosmonaut added that he did not feel there would be "any limitations" to enduring longer missions in space.

Michael Bungo, director of the Space Biomedical Research Institute at Houston's Johnson Space Center, is not so sure. "This is just one test case," he says. "The margin of error is considerable." The validity of the 5% figure, Bungo believes, also depends on whether bone-marrow testing was done at the preferred point -- the spine -- or at the heel bone, which he says the Soviets have done in the past. Besides, while total calcium loss may have been low, he is concerned that there still may be structural changes in Romanenko's bones that could make them more prone to fracture.

James Oberg, a veteran U.S. Soviet space watcher, is impressed by Moscow's achievement but points to other serious physical dangers inherent in extended flights deeper into space. Perhaps the most significant: cosmic rays and high- energy radiation from the solar wind. Earth-orbiting space travelers like Romanenko are protected from this potentially deadly radiation by the earth's magnetic field. But, says Oberg, "there is no real experience anywhere on the effects of long-term, deep-space radiation exposure." Even so, with Romanenko's performance the Soviets bolstered their commanding lead over the U.S. in long-duration space flights. Soviet space officials have decreed that the current crew of the space station Mir, Vladimir Titov and Musa Manarov, will stay in orbit for a full year.

With reporting by James O. Jackson/Moscow, with other bureaus