Astronauts Jasmin Moghbeli and Loral O’Hara conducted their first spacewalk outside the International Space Station (ISS) on Wednesday, working on a complex task. Their mission was to replace a bearing assembly in one of the lab’s solar array rotation mechanisms. However, this task took longer than expected, and they were unable to retrieve a failed electronics box as originally planned.
This spacewalk marked the first for Moghbeli and O’Hara, the fourth all-female excursion, and the first one since January 2020 when Jessica Meir and Christina Koch completed their third EVA (extra-vehicular activity).
The spacewalk, the 12th of the year, began at 8:05 a.m. EDT when Moghbeli and O’Hara switched their spacesuits to battery power.
Their primary objectives were to replace a degraded bearing assembly in one of the station’s two solar array rotation mechanisms and retrieve a failed communications component stored on an external platform for eventual shipment back to Earth for repairs. Astronauts Jasmin Moghbeli
O’Hara focused on replacing the bearing assembly in the station’s left-side solar alpha rotary joint (SARJ), which is responsible for rotating outboard solar arrays to optimize energy production. Each SARJ is equipped with 12 bearing assemblies that clamp onto a rotating 10.5-foot-wide “race ring.”
While O’Hara worked on unbolting the bearing assembly, Moghbeli removed a handling fixture that was no longer needed, creating space for the future installation of a roll-out solar array blanket.
As Moghbeli was taking pictures of the area where the new arrays would be installed, flight controllers requested her help in holding O’Hara in place as she struggled to loosen tight bolts securing the bearing assembly. The removal of the degraded bearing assembly took longer than expected, causing the crew to fall about an hour behind schedule.
Once the bearing assembly was finally replaced, O’Hara used a grease gun to lubricate the race ring, while Moghbeli repositioned an out-of-position ethernet cable on a nearby external camera.
Afterward, Moghbeli assisted O’Hara in using a power tool to tighten the bolts securing the replacement bearing assembly in place. Finally, Moghbeli made her way to an external storage platform where a failed S-band radio communications component was stored.
Originally, the plan was to remove the unit and bring it back to the ISS airlock for eventual return to Earth. However, due to the time lost in installing the bearing assembly, flight controllers decided to have Moghbeli prepare the unit for removal during a future spacewalk, with O’Hara assisting her towards the end of the EVA.