Marc Reagan (left) and Bill Todd, NASA Extreme Environment Mission Operations (NEEMO) project leads, have left the current NEEMO team in the National Oceanic and Atmospheric Administration (NOAA) Aquarius Underwater Laboratory to start their 17-day mission. The team comprises astronauts Dave Williams (team leader), Nicole Stott and Ron Garan, plus Dr. Tim Broderick of the University of Cincinnati. The astronauts are testing space medicine concepts and moon-walking techniques. The undersea laboratory is situated three miles off Key Largo in the Florida Keys National Marine Sanctuary, anchored 62 feet below the surface.