Related by context. Frequent words. (Click for all words.) 67 NASA 59 Nasa 56 human spaceflight 56 space shuttle 53 spaceflight 53 astronauts 51 orbiter 50 SpaceX 50 Space Shuttle 49 Dittemore 49 NASA Headquarters 48 spacecraft 48 astronaut 47 shuttle Discovery 47 space shuttles 47 Defense Secretary 46 orbiters 46 Discovery astronauts 46 EPA Administrator 46 ISRO 45 National Security Adviser 45 space shuttle Discovery 45 Bolden 45 Kennedy Space 45 JAXA 45 International Space Station 44 Mission Control 44 Interior Secretary 44 shuttle missions 44 SPACE.com 44 Charles Bolden 44 Secretary Steven Chu 43 NASA astronaut 43 shuttle astronauts 43 Space Station 43 shuttle fleet 43 National Aeronautics 43 spacewalk 43 shuttle Atlantis 43 liftoff 43 FAA Administrator 43 orbit 43 astronauts aboard 43 Hubble Space Telescope 43 SpaceShipOne 43 Space Shuttle Discovery 43 director Mike Leinbach 42 shuttle 42 Cape Canaveral 42 shuttle Endeavour 42 X #B 42 NOAA 42 Missile Defense Agency 42 Space Exploration 41 Boehlert 41 Earth orbit 41 Space Flight 41 Jet Propulsion Laboratory 41 Space 41 NASA Jet Propulsion Laboratory 41 Pentagon 41 spacesuit 41 Soyuz 41 Sean O'Keefe 41 Leinbach 40 Holdren 40 Ares 40 Shuttle 40 Space Agency 40 orbiting 40 LCROSS 39 Secretary Margaret Spellings 39 moon 39 Research Organisation ISRO 39 Sen. Barbara Mikulski 39 spacewalkers 39 NASA Ames 39 Hubble 39 Homeland Security Secretary 39 NNSA 39 Space shuttle Atlantis 39 Atlantis 39 Buzz Aldrin 39 Astronaut 39 Hubble telescope 39 Gehman 39 Arianespace 39 NASA Jet Propulsion 39 Astronauts 38 JPL 38 spaceship 38 space shuttle Endeavour 38 Chandrayaan 38 Inhofe 38 Cape Canaveral Air Force 38 spaceships 38 CEO Rick Wagoner 38 NASA Langley 38 Endeavour 38 Secretary Ray LaHood 38 White House