Astronauts Check Body Changes During Tests on Weightlessness

Astronauts aboard the shuttle Columbia drank water laced with oxygen isotopes, nitrogen and calcium Tuesday in tests to monitor body changes during weightlessness.

The crew members also gave each other shots of chemicals that were traced through their bodies to measure changes in blood volume, kidneys, bones and muscles. Blood, urine and saliva samples also were collected on the first full day of the planned two-week medical research mission.

In another test, the astronauts monitored their heartbeats with an ultrasound device developed by David Wolf, one of the crew’s two physicians. They also exercised on a stationary cycle and collected the droppings of laboratory rats.

The crew had to open the door on one of the two animal enclosures and turn on a fan to cool the 24 inhabitants. The enclosure was a few degrees warmer than desired.

“All the rats look pretty healthy and happy,” said Columbia’s veterinarian, Martin Fettman. “We’re just a little concerned about the rats in cage two because of the vacuum, the hurricane that goes by them with the cage door open and the (fan) on.”

The National Aeronautics and Space Administration wants the five men and two women to collect as much data as possible early in the flight, while the body is still adapting to weightlessness. Scientists said that is a major limitation of Russia’s space program--even though cosmonauts have spent as much as a year in orbit, it is difficult for them to gather medical data during the first few days.

Muscles weaken in space and bones soften. NASA wants to develop measures to counteract these and other side effects, such as diminished immunity, reduced red blood cells and loss of balance.

The only other shuttle mission devoted to medical research, a nine-day flight in 1991, indicated among other things that the body produces enough muscle protein in weightlessness but that the protein breaks down faster.

Tuesday, like launch day, was full of experiments. “I think that we’ll be fortunate if we can keep up this pace,” NASA program scientist Frank Sulzman said. “We know that for a 14-day mission we have to schedule things so that we don’t have the crew working nonstop.”