John M. Grunsfeld served as associate administrator for Science Mission Directorate at nasa from January 2012 to May 2016. He previously served as the deputy director of the Space Telescope Science Institute in Baltimore, managing the science program for the Hubble Space Telescope and the forthcoming James Webb Space Telescope. Grunsfeld is a veteran of eight spacewalks and five space shuttle flights to destinations such as Hubble Space Telescope, International Space Station, and Russian space station Mir. His background includes research in high-energy astrophysics and the emerging field of exoplanet studies with specific interest in future astronomical instrumentation. Grunsfeld was appointed professor of physics at Johns Hopkins University in 2010.