The two-man team replaced a sequential shunt unit electronics box, a voltage regulator, on the starboard truss that failed in mid-May. Although the station has since operated normally on seven of its eight power channels, the voltage regulator replacement is considered a high priority.

The astronauts started routing cables for the International Docking Adapter (IDA). In preparation for the arrival of new commercial crew vehicles to the ISS in late 2017 - which will use a brand new docking system - the existing docking ports on the ISS need to be converted to the new standard, before any commercial crew vehicles can dock to the outpost.

The astronauts unfurled and hooked up two more long cables and Terry Virts lubricated the grapple fixture on the end of the space station's robot arm (SSRMS).

They installed new antennas and cabling needed for communications between the station and commercial crew capsules bound for, or departing from, the new docking adapters.