 Gehrels was the Principal Investigator of the Swift mission and Deputy Project Scientist for the Fermi observatory.Swift is a three-instrument satellite launched in 2004 and designed to study GRBs and their afterglows.Since approximately 2009, it has become a community tool for observing transient and variable sources of all types including novae, supernovae, AGN, magnetars, galactic black hole and neutron stars, tidal disruption events, and comets.