John M. Grunsfeld, a veteran of five space flights, has logged more than 58 days in space, including 58 hours and 30 minutes in eight space walks. During his walks, he and his team performed numerous repairs and upgrades to the Hubble Space Telescope.

On the fifth and final Hubble servicing mission in May 2009, for which Dr. Grunsfeld served as the lead spacewalker in charge of the spacewalking and Hubble activities, the telescope got a major renovation which included the installation of a new wide field camera and a new ultraviolet telescope, new batteries, a guidance sensor, gyroscopes and other repairs.