Shuttle Crew Back On Ground

Space shuttle Columbia and its crew returned to Earth on Sunday, ending two weeks of brain research that was marred by unexpected animal casualties.

But the experiments were far from over.

Stretchers were carted to the landing strip so five of the seven astronauts could be carried off the shuttle in an attempt to preserve their weightless state.

It was a race against gravity: the sooner the astronauts and animals could be examined, the greater the likelihood of observing space-induced changes in the nervous system.

Columbia landed right on time at the Kennedy Space Center, where about 200 researchers waited with scalpels.

Columbia swooped through a clear noontime sky and touched down neatly on the runway. The trip added 6.4 million miles to the odometer of NASA's oldest shuttle.

Commander Richard Searfoss had only two functioning hydraulic power units for most of the hour-long descent. The cooling system for the third unit failed to work Saturday, and so Searfoss turned that unit on just minutes before touchdown so it would not overheat.

Only the rodent researchers knew for sure what they were getting back.

The astronauts kept close watch on the 170 rodents that rocketed into orbit with them on April 17, especially after 52 of 96 baby rats died. The surrogate mother rats could not or would not nurse the young animals in space.

Because the containers for the fish, snails, and crickets were inaccessible aboard Columbia, the astronauts did not know how those animals fared in weightlessness.

The post-flight dissection plan called for the fish and crickets to be placed on ice and frozen to death, the snails to be doused in alcohol, and the rats to be decapitated or overdosed with anesthesia. The work was expected to take hours.

Scientists hoped to get back more animals than he sent up.

Michael Wiederhold, a researcher at the University of Texas Health Science Center at San Antonio, launched 60 adult snails aboard Columbia. The last time he flew snails in space, "they just went to town" and yielded 500 offspring. Because this mission was longer, he was hoping for 700.

Reproduction seems to be a snap for snails in space, Wiederhold said, because there's little in the shuttle aquarium for them to run into and grab onto except one another.

The big question, for the astronauts anyway, was whether they would return to space this summer and do it all over again. The National Aeronautics and Space Administration said it will decide this eek whether to repeat the Neurolab mission in August to fill the flight gap created by the anticipated delay in space station construction.

By Marcia Dunn