Spacewalkers finish ISS battery upgrades, replace cameras

NASA astronaut Mike Hopkins works on the P4 truss during the first spacewalk of 2021. During their second spacewalk, he and astronaut Victor Glover worked to finish a battery upgrade project that was started four years ago. Credit: NASA

In the second spacewalk in less than a week, two NASA astronauts ventured outside the International Space Station to wrap up a battery upgrade project started four years ago, and completed various other small tasks.

NASA astronauts Mike Hopkins and Victor Glover, both members of the seven-person Expedition 64 crew, ventured outside the space station’s Quest airlock at 7:56 a.m. EST (12:56 UTC) Feb. 1, 2021, for U.S. Extravehicular Activity 70. Their tasks included installing a final lithium-ion battery and an adapter plate on the P4 truss segment, replacing three external high-definition cameras and performing several get-ahead tasks.

Hopkins was the lead spacewalker, EV 1, and wore the suit with red stripes and Glover wore the suit with no stripes and was designated EV 2. The spacewalking duo made quick work of all of their tasks with the outing lasting 5 hours and 20 minutes.

The final battery installed concluded a four-year-long process of replacing the 48 nickel-hydrogen batteries launched with the original truss segments during space station assembly. Only 24 more-efficient lithium-ion batteries were needed. As such, each new unit needed an adapter plate to complete the original two-battery series circuit.

Six batteries and adapter plates were brought to the ISS over four autonomous Japanese Kounotori missions starting with Kounotori 6 at the end of 2016. Those batteries were installed via spacewalking astronauts the following month. Most of the old nickel-hydrogen units were disposed of by the Japanese cargo ship as well.

When the batteries on the P4 truss were replaced in March 2019, one of the batteries on the 4A channel failed not long after being installed. The battery was removed in a later spacewalk and an old nickel-hydrogen battery was re-installed until a replacement could be sent into orbit.

That replacement was flown to the ISS during SpaceX’s CRS-19 cargo mission in December 2019.

Once that work was finished, Hopkins moved onto his next task, which was to remove another H-fixtured to make way for the eventual installation of upgraded solar arrays to augment the current aging arrays.

NASA astronaut Mike Hopkins, right, and Victor Glover, right, seen in their spacesuits before the first spacewalk of 2021. NASA astronaut Kate Rubins, in the black shirt, worked with Japanese astronaut Soichi Noguchi, in the red shirt, assisted the spacewalking duo from inside the ISS during both EVAs. Credit: NASA

Those new solar arrays are set to be launched as soon as May 2021 aboard SpaceX’s CRS-22 cargo Dragon.

Next, Glover, with the help of the robotic Canadarm2, began installing three high-definition cameras.

The first was located on the S1 truss. With the help of Hopkins, the two worked to replace a failed unit, which was placed in the airlock after the task was completed.

The second camera installation was located on a boom on the Destiny laboratory module. Glover installed a new high-definition camera alongside existing external cameras.

The third camera installation didn’t require the robotic arm. As such, Glover got off the device and proceeded to make his way to the Japanese Kibo module where he worked to replace a camera mounted on the wrist segment of the Japanese Experiment Module robotic arm.

Once those tasks were completed, the duo moved on to get ahead-tasks. That included seeing Hopkins removing another H-fixture on the S4 truss while Glover pre-positioned several foot-restraints to support spacewalks focusing on future solar array upgrades.

Hopkins and Glover returned to Quest and began repressurizing the airlock at 1:16 p.m. EST (18:16 UTC), officially ending U.S. EVA-70.

Overall, this was the 234th spacewalk in support of ISS assembly and maintenance and the second in 2021. The total time spent outside the ISS by astronauts and cosmonauts since 1998 now totals 61 days, 7 hours and 7 minutes.

This was Hopkins’ fourth outing bringing his cumulative career time outside to 25 hours, 14 minutes. Glover was on his second (his first was last week), bringing his total time to 12 hours 16 minutes.

NOTE: While this article was written by Derek Richardson, it was originally published at SpaceFlight Insider.