It was the 10th Spacewalk for both Cassidy and Behnken tying them with former astronauts Michael Lopez-Alegria and Peggy Whitson for the most spacewalks by an American Astronaut.
Behnken and Cassidy performed a number of tasks designed to upgrade station systems. Their first task will be to install a protective unit to store tools for use by the Canadian Space Agency’s Dextre robot. The storage unit also includes two Robotic External Leak Locator (RELL) units that Dextre can use to detect leaks of ammonia, which is used to operate the station’s cooling system.
The astronaut duo then worked on removing two lifting fixtures at the base of station solar arrays on the near port truss, or backbone, of the station. The “H-fixtures” were used for ground processing of the solar arrays prior to their launch.
They then moved on to work to prepare the outside of the Tranquility module for the arrival later this year of the Nanoracks commercial airlock on a SpaceX cargo delivery mission.
Finally, they routed ethernet cables and removed a lens filter cover from an external camera.
Chris Cassidy has now logged 54 hours 51 minutes of spacewalk time – the 9th most of all time.
Robert Behnken has logged 61 hours 10 minutes of spacewalk time – the 4th most of all time.