Astronauts take time to be tourists

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Sleeping patterns part of experiment

Tuesday, November 3, 1998

BY TIM BONFIELD
The Cincinnati Enquirer

John Glenn, left, and commander Curt Brown, right, listens as Spanish astronaut Pedro Duque speaks to schoolchildren in Madrid. (AP - NASA TV photo) | ZOOM |

At the halfway point in their nine-day mission, the space shuttle Discovery crew got a half-day off Monday, giving them time to look out the windows, talk to their families, take crew photos and relax. All the projects on STS-95 are running on time or ahead of schedule, said Paul Hill, mission flight director.

John Glenn and Japanese astronaut Chiaki Mukai reported no problems after spending their first of four nights with their heads wrapped in special sleep monitoring sensors.

Lack of sleep is a crucial issue in space, because it reduces alertness and performance. In addition, the effects of sleep loss are cumulative. That means, the longer the flight, the more problems can be expected.

The sensors can tell whether the subject is dreaming (although it cannot record the content of the dream) and they can tell when the subject is snoring. One night's worth of data from the sleep nets for one subject can fill about 1,000 printed pages.

This information will be combined with results of repeated cognitive skills tests taken during the flight to track the effects of sleep loss on mental performance, said Dr. Charles Czeisler, a Harvard Medical School professor and principal investigator on the STS-95 sleep study.

Rather than the ideal eight hours a night, astronauts have reported getting about six hours of sleep a night. So far, Mr. Glenn is reporting about the same results.

Within four to six days, losing that much sleep a night is similar to skipping an entire night of sleep, Dr. Czeisler said.

Sleep issues matter to NASA because people of varying ages and health conditions are expected to live for months at a time aboard the International Space Station, once it gets built. The five-year construction project begins later this month.

To assure a decent night's sleep, shuttle astronauts have tried various sleeping pills with mixed results. NASA continues to search for a medication that actually helps people sleep yet has no lingering effects after waking up.

Today's mission highlight will occur about 3:30 p.m. EST, when Discovery uses its robot arm to capture the Spartan satellite.