Having successfully repaired/upgraded the Hubble Space Telescope in what was easily the most complicated in-space repair mission in history, the Shuttle and Hubble depart the company of one another.
Taken from NASA image caption: An STS-125 crew member aboard the Space Shuttle Atlantis captured this still image of the Hubble Space Telescope as the two spacecraft begin their relative separation on May 19, after having been linked together for the better part of a week. During the week five spacewalks were performed to complete the final servicing mission for the orbital observatory.