In May 2009, NASA astronaut and University of Chicago alumnus John Grunsfeld boarded the last Space Shuttle to visit the Hubble Space Telescope. Dr. Grunsfeld successfully upgraded the telescope with new cameras and instruments and made repairs to allow the telescope to begin a new journey of discovery. During the course of 12 days in orbit the Hubble Servicing Mission 4, or STS-125, allowed two teams of astronauts to perform 5 space walks. In this talk, Astronaut Grunsfeld will describe the adventure of working in orbit on the Hubble Space Telescope and the exciting scientific results that the new instruments are providing.