Removing a cover that has been in place to protect a port on the Unity node, the location where Tranquility was attached robotically halfway through the spacewalk. Next, the spacewalkers removed and stored a spare parts platform from the Special Purpose Dexterous Manipulator, or Dextre, a two-armed space station robot capable of handling delicate assembly tasks currently performed by spacewalkers. Finally, they installed four electronics systems cables between Unity and Tranquility to bring the new node to life.

Installing ammonia plumbing connectors between Unity and Tranquility and covered them with thermal insulation. When turned on, the ammonia will provide cooling to Tranquility. Then they prepared a port on the Earth-facing side of Tranquility for the flight day 8 relocation and attachment of the Cupola.

Turning on the ammonia cooling lines between Unity and Tranquility, installing heater and data cables on Tranquility, removing insulation and launching locks from the newly installed Cupola, and installed handrails on the outside of Tranquility.