NASA astronauts Robert Behnken and Chris Cassidy concluded their spacewalk at 12:41 p.m. EDT, after five hours and 29 minutes. The two NASA astronauts completed a number of tasks designed to upgrade International Space Station systems.
They began by installing a protective storage unit that includes two Robotic External Leak Locator (RELL) units the Canadian Space Agency’s Dextre robot can use to detect leaks of ammonia, which is used to operate the station’s cooling system.
Behnken and Cassidy then removed 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 completed tasks 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. After its installation, the airlock will enable be used to deploy commercial and government-sponsored experiments into space.
They also routed ethernet cables and removed a lens filter cover from an external camera.
This was the 10th spacewalk for each astronaut, tying them with Michael Lopez-Alegria and Peggy Whitson as the only other U.S. astronauts to complete 10 spacewalks. Behnken has now spent a total of 61 hours and 10 minutes spacewalking, which makes him the U.S. astronaut with the third most total time spacewalking, behind Lopez-Alegria and Andrew Feustel, and the fourth most overall. Cassidy now has spent a total of 54 hours and 51 minutes spacewalking and is ninth on the worldwide list for total time spacewalking.
Space station crew members have conducted 231 spacewalks in support of assembly and maintenance of the orbiting laboratory. Spacewalkers have now spent a total of 60 days, 12 hours, and 3 minutes working outside the station.