Sunday, January 15, 2017

ISS Spacewalkers Replace Batteries, Part 2

Astronaut Shane Kimbrough exits the station through the Quest airlock. His suit had the red stripe, allowing flight controllers to easily identify which astronaut was visible on camera.

On Friday January 13, American EVA 38 took place to complete the battery change-out that was the focus of last week's spacewalk. Expedition 50 commander Shane Kimbrough led the EVA, making his fourth spacewalk, while he was joined by ESA astronaut Thomas Pesquet, who was making his first spacewalk.

Kimbrough takes a great selfie, focusing on his reflective helmet which shows the Earth in the background. It's also a great view of the helmet assembly, with its extra lighting, cameras for astronaut POV, and solar protection covering on visor.

The mission of this EVA was to complete the switchout of the older Nickel-Hydrogen truss batteries with the newer Lithium-Iron batteries. This power changeout has been underway for a long time, as astronauts have used several spacewalks and several robotic arm procedures to replace cables, switch power routings, and finally relocate old batteries to storage and install new batteries on the Truss.

Just hanging out, over 180 miles above the Earth. Easy Peasy. Picture from Thomas Pesquet's camera.

The station's Truss battery sections are in 4 parts, due to how the truss components were launched and assembled. The oldest Truss is designated P6. It's oldest batteries were changed out to newer lithium-hydrogen batteries (new then)by shuttle astronauts back in 2009 and 2010.But now the batteries will need to be replaced so that the station can continue its work-life towards 2024, so new batteries are required, and the new lithium-ion batteries are the new technology. It's planned to take up to 4 years to replace all the Ni-H2 batteries. These spacewalks replaced the oldest Ni-H2 batteries on Truss S-4.

Inside part of the S-4 Truss segment.

The battery change-out was completed a couple of hours ahead of schedule, so the astronauts used the rest of the EVA time to accomplish some tasks which would have been done on the next scheduled spacewalk. The total time of the spacewalk was just under six hours.

Back inside. Peggy Whitson assisted the astronauts in removing themselves from the EVA suits.