Astronauts went spacewalking Friday to provide some necessary focus to the International Space Station's robot arm.
The main job for commander Randy Bresnik and teacher-turned-astronaut Joe Acaba was to replace a blurry camera on the new robotic hand that was installed during a spacewalk two weeks ago. The two men were supposed to go spacewalking earlier this week, but NASA needed extra time to rustle up the repair plan.
Sharp focus is essential in order for the space station's robot hand to capture an arriving supply ship. The next delivery is a few weeks away, prompting the quick camera swap-out.
Orbital ATK, one of NASA's commercial shippers, plans to launch a cargo ship from Virginia on November 11.
Acaba was barely outside an hour when he had to replace one of his safety tethers, which keep him secured to the orbiting outpost and prevent him from floating away.
Mission Control noticed his red tether seemed frayed and worn and ordered Acaba to "remain put" with his good waist tether locked to the structure as Bresnik went to get him a spare.
Spacewalking astronauts always have more than one of these crucial lifelines in case one breaks. They also wear a jetpack in case all tethers fail and they need to fly back to the space station.
This was the third spacewalk in two weeks for the space station's U.S. residents. Bresnik performed the first two with Mark Vande Hei.
As they ventured out, Bresnik noted they were flying over Puerto Rico.
"Get out of here," replied Acaba, the first astronaut of Puerto Rican heritage.
Acaba's parents were born there, and he still has family on the hurricane-ravaged island.
"There's a whole line of people looking up and smiling today as you get ready to head out the door," Bresnik said.
Friday's spacewalk should be the last one for the year. Early next year, astronauts will replace the hand on the opposite side of the 58-foot robot arm, Canada's main contribution to the space station. The original latching mechanisms are showing wear and tear since the arm's launch in 2001.
The 250-mile-high complex is currently home to three Americans, two Russians and one Italian.