Two NASA astronauts gave a robotic arm a hand up — or rather, a replacement wrist joint — during a successful spacewalk outside the International Space Station on Tuesday (June 30).
Chris Williams and Jessica Meir, both flight engineers on the station's Expedition 74 crew, spent seven hours and 20 minutes repairing the Canadarm2 remote manipulator system (RMS) after it was observed drawing current but not moving as expected in late May. The 58-foot-long (18 meters) arm has been in regular use since it was installed on the orbiting outpost in April 2001.
"For over 25 years, the Canadarm2 has been a crucial part of the International Space Station. The arm was key to our orbiting laboratory and continues to be a workhorse that we rely on. Whether it is performing maintenance or replacing equipment, moving and operating payloads, catching cargo vehicles or helping us out during spacewalks, the arm has played and will continue to play an essential role in our work on orbit," Williams said as the spacewalk ended.
"It is also a testament to international cooperation," he added. "Canada, the U.S. and the world have come together to make this program a success. We are honored … that we were able to give the arm a helping hand."
Williams and Meir, each wearing a NASA extravehicular mobility unit (EMU), ventured outside the Quest airlock soon after switching the spacesuits to battery power at 8:20 a.m. EDT (1220 GMT) on Tuesday. They made quick work of transitioning to their work station, where they retrieved a spare wrist joint by using a power tool (pistol grip unit) to unbolt it from an exterior equipment panel.
They then turned their focus to the arm, which was positioned nearby. They removed the old unit and installed the new joint (no. 5), bolting it in place. Williams and Meir brought the faulty joint back into the space station to be returned to Earth for analysis and possible refurbishment.
The astronauts completed their work on the arm by reattaching its latching end effector, or hand, which the arm uses to grapple objects and inchworm across the exterior of the station. Mission Control confirmed that the arm had good power connections after the astronauts' work.
Williams and Meir returned to the Quest airlock and began its depressurization at 3:40 p.m. EDT (1940 GMT), marking an end to the spacewalk.
Tuesday's EVA (extravehicular activity) marked the fourth time in history that spacewalkers have worked to service the Canadarm2. Previously, another wrist joint was replaced and both of the arm's end effectors were swapped out for spares.
"We are thrilled to have repaired the mighty Canadarm2 just in time for Canada Day tomorrow! We hope that all in Canada and everyone around the globe can celebrate this achievement," said Meir.
Expedition 74 flight engineers Jack Hathaway of NASA and Sophie Adenot of the European Space Agency assisted Williams and Meir by helping them to don and doff their spacesuits and maneuvering Canadarm2 into position for the astronauts' repair work.
This was Williams' second spacewalk and the fifth for Meir. Williams has now logged 14 hours and 22 minutes, including a previous EVA with Meir. Meir has totaled 36 hours and 6 minutes, including the first all-female EVA in 2019.
Tuesday's spacewalk was the 280th in support of International Space Station assembly, maintenance, and upgrades since 1998.
