Abort of a planned six-hour spacewalk

Installing a new circuit breaker to restore power to one of four gyroscopes that help orient the complex

Replacing several materials exposure experiment packages and a thruster contamination monitor, installing reflectors and communications equipment needed for the docking of a new European Space Agency cargo ship

Installing three antennas on the exterior of the Zvezda Service Module that will aid the automated docking of a new Station supply craft, the European Automated Transfer Vehicle; replacing of a pump panel on the Zarya module; installation of guides for spacesuit tethers on Zarya handrails; installation of handrail covers near the Pirs Docking Compartment hatch

Deploying and retrieve several Russian experiments on the station's exterior and installing a device to measure electromagnetic forces imparted on station hardware as the complex moves through low Earth orbit

Installing of EXPOSE-R, a European experiment that exposes seeds and spores to the space environment

The astronauts refilled radiators with ammonia. They also completed venting the early ammonia system, lubricated a left-side solar joint and parts of Dextre, a two-armed space station robot capable of handling delicate assembly tasks currently performed by spacewalkers.

Installing a grapple, or handle for the robotic arm on the station to grab, on the Zarya module to support robotic operations based from the Russian segment. They also installed additional cables to provide backup power to the Russian portion of the space station.

Fincke and Chamitoff stowed the shuttle's 50-foot boom on the right-side truss on a permanent stowage fixture, retrieved the grapple from the station's left-side truss and used it as a replacement for the grapple currently on the boom. They then released restraints from one of the arms on Dextre and replaced thermal insulation on one of the spare gas tanks for the Quest airlock.