Shuttle Crew Do Depressurization, Radio Tests
Two astronauts slipped into a vacuum container Saturday for an hour of depressurization intended to ease their transition from space to Earth at the end of NASA’s longest shuttle flight.
On the lighter side, Columbia’s five-man, two-woman crew tested a shuttle amateur radio experiment featuring “Tonight Show” host Jay Leno.
For the vacuum container experiment, Lawrence DeLucas was the first Columbia crew member to wriggle into the white, waist-high sack, which floated horizontally above a platform to which it was strapped. The vessel was secured tightly around his waist, and he read a flight manual now and then to pass the time.
Pressure inside the container gradually was reduced, forcing blood from the top of his body, where it accumulates in weightlessness, into his legs. The stress on his heart was about the same as it would be if he were standing on Earth.
Payload commander Bonnie Dunbar operated the blood-pressure and heart-monitoring instruments connected to DeLucas.
They switched roles a few hours later: Dunbar was the test subject and DeLucas the tester.
Scientists believe negative pressure on the legs may improve astronauts’ readjustment to gravity after space flight. NASA estimates that about 5% of all astronauts become faint upon landing as the blood rushes from their heads and chests into their legs.
In other orbital work, physicist Eugene Trinh used sound waves to make liquid drops swirl and shimmy inside a small chamber as part of a fluid physics experiment. He had to mop up the inside of the chamber after one of the bubble-like drops burst into brilliant droplets.
Researchers had been perplexed by the drops’ persistent spinning, but said Saturday the astronauts seemed to be gaining control of the acoustics.
“We’re still flexing the facility’s muscles, learning how to manipulate drops in microgravity,” said principal investigator Robert Apfel of Yale University.
