By
The Associated Press
SPACE CENTER, Houston - Two astronauts floated outside space shuttle Atlantis yesterday, performing chores on the international space station during the 100th spacewalk in the U.S. space program.
Thomas Jones and Robert Curbeam Jr. continued the string of space excursions started in 1965 by Edward H. White II. White's 21-minute spacewalk was on the mission called Gemini 4.
Jones and Curbeam were to put the finishing touches on the international space station's newly installed science laboratory, Destiny, and perform some final chores during their spacewalk - the third and last of their mission.
The bulk of their mission's objective - to mount and install the $1.4 billion Destiny on space station Alpha - was done on their previous spacewalks.
The first task Jones and Curbeam completed during yesterday's scheduled five-hour excursion was the installation of a spare communications antenna for Alpha.
"Outstanding, you guys are just awesome," Mission Control told them.
The pair unlatched a space station radiator which was then deployed by computer commands sent by the shuttle crew.
Curbeam photographed coolant lines that leaked and sprayed him with ammonia during the first spacewalk on Saturday. Flight controllers were going to examine the photos to see if there were any problems with the lines.
Also photographed were latches that never fully locked into place on the base of the huge solar panels installed in December. The pictures could help determine how the latches might be fixed during a future mission.
Before the spacewalk wound up, Jones and Curbeam also planned to practice for disaster, trying out emergency techniques that could be used to assist an incapacitated spacewalker. Each astronaut will take a turn playing a limp crewman while the other pulls him back into the shuttle.
On Tuesday, Alpha reached two milestones, its attitude in orbit was controlled by solar-powered gyroscopes instead of small thruster rockets, and the station was controlled by Americans rather than Russians.
On Mission Control's cue, computers inside Destiny sent commands to four gyroscopes that were delivered by shuttle astronauts in the fall. The gyroscopes, in turn, took over the steering of the space station from the fuel-guzzling Russian thrusters.
The computers - and the gyroscope motors - were powered by electricity from the giant solar wings installed in December.
When the gyroscopes were in control, so was NASA's Mission Control in Houston. Until that moment, flight controllers in Russia had always been in charge.
Mission directors were trying to solve one problem in setting up Destiny: Its carbon dioxide-removal system was not working because of a bad pump.
Even with the glitch, flight controllers said they were pleased with how smoothly the mission and station operations have gone. The shuttle undocks tomorrow and is scheduled to return to Earth on Sunday.
"This has been an amazingly complex mission when you look at all the new systems being activated," space station flight director Andy Algate said.
