The Dangers of Spaceflight

Spaceflight has a good safety record, but there have been fatal accidents involv­ing astronauts. The first person to be killed during a mission was Soviet cos­monaut Vladimir Komarov in April 1967. Veteran of an earlier flight in the three-man Voskhod 1, Komarov was fly­ing alone in the new Soyuz craft in 1967. It seems the spacecraft began to spin while still in orbit and then over­heated when trying to reenter the atmosphere. Komarov was killed during reentry.

Three U. S. astronauts were trapped and killed in the Apollo 1 fire during ground tests in January 1967. They were Gus Grissom, Ed White (the first American to “walk” in space, in June 1965), and Roger Chaffee.

The worst fatalities to U. S. astronauts involved the Space Shuttle, first flown with astronauts on board in 1981. On January 28, 1986, the Space Shuttle Challenger broke up shortly after liftoff. All seven astronauts were killed. After modifications, the Space Shuttle returned to space, but tragedy struck again on February 1, 2003. This time it was Columbia, nearing completion of its twenty-eighth mission. During its descent, the spacecraft disintegrated high above Texas. Again, all seven astronauts on board died.

Astronauts do not appear to suffer any serious health consequences from short flights. Over time, however, the absence of gravity affects the human body. Astronauts find that their muscles

waste and bones weaken during flights lasting weeks or months. Cosmonaut Yuri Romanenko returned to Earth in 1987 after 326 days in space, aboard the Soviet space station Mir. He found his calf muscles had shrunk 15 percent in spite of workouts on a treadmill and exercise bike.

During periods of prolonged weight­lessness, astronauts grow 1 to 2 inches (2.5 to 5 centimeters) taller because the bones in their spines spread apart. Back on Earth, the bones close up again, and the astronauts soon return to their normal height.