Replacing a depleted nitrogen tank and a device used to help the flow of coolant from the truss, the backbone of the station. They also removed thermal covers from the Japanese Kibo module to inspect the berthing mechanism where the module's exposed facility will be installed during the STS-127 mission in 2009. They also started inspecting, cleaning and lubricating the starboard SARJ and begin replacing 11 of 12 trundle bearings. One was replaced during the STS-124 mission in June 2008.

Completing starboard SARJ cleaning, lubricating and trundle bearing work.

Removing several thermal covers on the port SARJ. Kimbrough lubricated the port SARJ, while Bowen reinstalled the thermal insulation covers (removed on first EVA) on Kibo. He then installed two GPS antennas on Kibo's logistics module, while Kimbrough installed a new TV camera on the truss.

Installing a spare space-to-ground Ku-band antenna on the station's truss, or backbone. Then they installed a new tool platform on Dextre. The spacewalkers breaked the torque on bolts holding batteries in place on the truss, in preparation for their removal and replacement on the second and third spacewalks. Battery preparation work was deferred from STS-131 to this flight.

Removing and replacing four of the six batteries on the port truss to store electricity from the solar arrays on that truss. The used batteries were installed on the cargo carrier for return to Earth on Atlantis. In addition to the original tasks Bowen and Good relieved a snagged cable that is preventing full use of the laser imager and video camera. The equipment is located on the Orbiter Boom Sensor System.

They installed a power extension cable between the Unity and Tranquility nodes to provide a contingency power source should it be required. The spacewalkers moved the failed ammonia pump module that was replaced in August 2010 from an attachment bracket to a stowage platform adjacent to the Quest airlock. Drew and Bowen installed a piece of hardware that will go under a camera on the truss. The hardware will tilt the camera to provide clearance for a spare part to be installed on a future mission. They next replaced a guide for the rail cart system used for moving cargo along the truss. The guides were removed when the astronauts were performing work on the station's starboard Solar Alpha Rotary Joint, which rotates the solar arrays to track the sun.

The astronauts removed thermal insulation from a platform, while Bowen swaped out an attachment bracket on the Columbus module. Bowen then installed a camera assembly on the Dextre robot then removed insulation from Dextre's electronics platform. Drew installed a light on a cargo cart and repair some dislodged thermal insulation from a valve on the truss then remove other insulation from Tranquility. The final task was be to "fill" a special bottle with space for a Japanese education payload. The bottle will be part of a museum exhibit for public viewing.