Restoration of a failed computer system returned life to a regular rhythm on the international space station Sunday, as two astronauts completed the fourth spacewalk since space shuttle Atlantis docked with the outpost a week ago.
“We’re slowly moving back into a normal mode of operations,” station commander Fyodor Yurchikhin radioed Mission Control in Moscow.
The “normal mode” included the last spacewalk of the mission, a previously unscheduled fourth trip outside the space station that finished up tasks originally scheduled for last Friday’s third spacewalk. Astronauts on the third spacewalk had the unplanned job of repairing a thermal blanket, which had peeled back near Atlantis’ tail during the June 8 launch.
The nearly 6½-hour spacewalk ended with astronauts Patrick Forrester and Steven Swanson completing nearly all of their tasks.
They activated a rotating joint — their top priority — on the outpost’s newest segment so a new pair of solar wings can track the sun and provide power to the station. The solar arrays were delivered to the space station by Atlantis.
The astronauts also set up a new camera stanchion outside the station’s newest segment and a computer network cable between the United States and Russian sides of the space station. They were not able to bolt down a problematic debris shield and instead secured it in place with tethers.
Overnight, flight controllers on the ground planned to give the rotating joint a small test by moving it 5 degrees. A more thorough test to see whether the solar arrays track the sun was in store for later in the day Monday.
Flight controllers on Monday were also set to conduct a final test on the health of Russian computers aboard the space station. The computers, which control orientation and oxygen production, crashed last week.
Yurchikhin and Russian cosmonaut Oleg Kotov got four of the six computer processors operating again on Friday. The remaining two were brought back online on Saturday but then flipped back off to be “in cold standby mode” so that they could be used if needed.
The testing of the space station’s thrusters will determine whether the computers are ready to handle controlling the station’s orientation or whether Atlantis needs to spend another day at the outpost. During the computer meltdown, Atlantis’ thrusters were used to help the station maintain its position.
“That will finish checking out all the different attitude control systems, and again we’re confident that it’s gonna work, but it will be a good double-check just to make sure everything is in the proper configuration,” flight director Kelly Beck said of Monday’s test.
With the exception of an oxygen generator, all of the space station systems that were powered down when the computers failed were back running.
Atlantis is set to undock on Tuesday and land Thursday in Cape Canaveral, Fla.
While the seven-member crew of Atlantis and the three-man crew of the space station spent Father’s Day 220 miles above Earth, the holiday didn’t slip the minds of the nine fathers at the outpost who collectively have 24 children.
“Happy Father’s Day to everybody downstairs,” said U.S. astronaut Clay Anderson.