Spacewalkers Install New Solar Array Motor, Finish Inspections

Image: Dan Tani (left) carries the solar array motor back to the Quest airlock while Peggy Whitson prepares for the SARJ inspection. Image credit: NASA TV

Expedition 16 Commander Peggy Whitson and Flight Engineer Dan Tani finished their spacewalk at 12:06 p.m. EST Wednesday. They spent 7 hours and 10 minutes outside the International Space Station on the starboard side of the truss structure.

The spacewalkers removed and replaced a Bearing Motor Roll Ring Module (BMRRM) that experienced electrical failures in early December. The BMRRM, or “broom”, drives the solar arrays as they tilt towards the sun maximizing power generation.

While the spacewalkers were still outside, Mission Control switched on the new BMRRM and rotated the solar arrays attached to the Beta Gimbal Assembly.

Whitson and Tani then inspected the Solar Alpha Rotary Joint (SARJ). The SARJ experienced electrical spikes last year and previous inspections revealed contamination and debris. Also, video inspections of the SARJ took place over the weekend providing data for engineers on the ground.