Testing thermal protection system repair techniques and installation of the External Stowage Platform-2 Attachment Device (ESPAD) on the space station

Replace of a failed International Space Station attitude control gyroscope

Attach of a massive external tool box to the space station's Quest airlock module; mounting an experiment package on the top of the station's solar array truss; and remove two "gap fillers" sticking up between heat shield tiles on Discovery's belly

They completing the modification kits for the IROSA solar arrays to be delivered to ISS later this year.