Two NASA astronauts completed the penultimate set of battery replacements outside the International Space Station, advancing a multi-year project to upgrade the power system for the orbiting laboratory.
Expedition 63 commander Chris Cassidy and Bob Behnken, who launched on SpaceX’s Crew Dragon spacecraft in late May, conducted their second spacewalk together on Wednesday (July 1), five days after beginning work on Battery exchange for one of the two power channels at the end of the station. the starboard armor (S6) still needs updating.
The spacewalk began at 7:13 am EDT (1113 GMT) when Cassidy and Behnken switched their space suits to internal power.
Video: NASA space walkers work outside the space station to swap batteries
In pictures: Expedition 63 mission to the International Space Station
Working alongside a platform supported by the station’s Canadarm2 robotic arm, the astronauts recovered and installed one more lithium-ion battery and one more adapter plate, adding to the two new batteries and two adapter plates that put the 26 in place. of June. She removed the sixth and last oldest nickel-hydrogen battery and stored it on the platform for disposal.
Each new battery is about half the size of a refrigerator, or 40 inches long by 37 inches wide by 19 inches high (101 by 94 by 48 centimeters). Old nickel-hydrogen batteries weigh 365 pounds. (165 kilograms) each. Lithium-ion replacements weigh 428 pounds. (194 kg).
Since the new batteries have more capacity, one lithium ion battery (and an adapter plate) can replace two nickel-hydrogen batteries. Since January 2017, astronauts have been working to upgrade each of the station’s eight power channels with three lithium-ion batteries instead of their original six nickel-hydrogen batteries.
Related: Photos from the spacewalk: the International Space Station gets a power upgrade
The new batteries have been delivered and discarded by Japan’s H-II Transfer Vehicles (HTV), the last and last of which arrived at the space station in May.
Cassidy and Behnken’s work on Wednesday completed the battery upgrade to the station’s IB power channel, leaving only channel 3B for a future set of two spacewalks. Flight controllers at NASA’s Mission Control Center in Houston verified that the new battery was operational.
Having accomplished the main task of extravehicular activity (EVA), the astronauts set about making several “breakthroughs.” First, they loosened the screws that held the final set of nickel-hydrogen batteries and relocated the fulcrums to prepare for the next pair of spacewalks scheduled for later this month.
The duo then broke up, heading to separate parts of the space station. Cassidy routed new power and ethernet cables into truss S3 to prepare for the installation of a new external wireless communications system. The power and data going through the cables will support an improved high-definition (HD) camera and increase the coverage area for helmet-mounted wireless cameras for future spacewalkers.
Meanwhile, Behnken made his way to the end of the starboard armor to remove a no longer needed device called “Accessory H” from the base of one of the solar array masts, which was installed before the array was launched. . The removal, however, did not go as planned.
“I have been applying as much force as I can to try to do it, but he is not interested in getting out,” Behnken informed Mission Control after trying to use various tools to remove the attachment from the mast. “I think the best answer may be a longer tool inserted into the anchor point, although that could break the anchor point. I can pull it pretty well, but it doesn’t really move at all.”
“We don’t think there is anything else we can do to remove it, so we will have to reevaluate future EVAs,” replied astronaut-capcom Jasmin Moghbeli, canceling the removal attempt from the ground.
Giving up the removal of the H-Fixture, Behnken met Cassidy on the S3 truss to help route the new Ethernet cable before they both returned to the Quest Lock to head to the space station. The spacewalk ended at 1:14 pm EDT (1714 GMT) after 6 hours and 1 minute.
Related: The International Space Station: inside and outside (infographic)
Wednesday’s spacewalk was the 229th in support of the assembly and maintenance of the space station. It was the eighth spacewalk for both astronauts.
Cassidy has now spent a total of 43 hours and 22 minutes and Behnken has spent a total of 49 hours and 41 minutes of spacewalk.
Robert Pearlman is a contributing writer for Space.com and editor of collectSPACE.com, a Space.com partner site and the leading publication of space history news. Follow collectSPACE on Facebook and on Twitter at @collectSPACE. Follow us on Twitter @Spacedotcom and Facebook.
