John Mace Grunsfeld

John Mace Grunsfeld , PhD, is an astrophysicist and a NASA astronaut. He has flown five times on the Space Shuttle, including three Hubble servicing missions. He has served as the Associate Administrator for the Science Mission Directorate, the NASA Chief Scientist, and as the Deputy Director of the Space Telescope Science Institute.

John Mace Grunsfeld , PhD, is an astrophysicist and a NASA astronaut. He has flown five times on the Space Shuttle, including three Hubble servicing missions. He has served as the Associate Administrator for the Science Mission Directorate, the NASA Chief Scientist, and as the Deputy Director of the Space Telescope Science Institute. See less