Related by context. Frequent words. (Click for all words.) 74 Christa McAuliffe 58 Challenger exploded 52 astronaut 52 McAuliffe 52 astronauts 51 space shuttle 51 Kalpana Chawla 47 Orion spacecraft 45 Ilan Ramon 45 crewmates 45 spaceflight 45 astronauts aboard 43 NASA astronaut 43 Apollo astronauts 43 Space Shuttle Columbia 43 NASA 43 shuttle missions 42 Russian Soyuz rocket 42 manned spacecraft 42 Daniel Tani 42 shuttle Discovery 42 shuttle Atlantis 42 manned spaceflight 42 spaceship 41 Alan Shepard 41 Soyuz craft 41 liftoff 41 spacecraft 41 NASA Space Shuttle 41 shuttle fleet 40 Skylab 40 Orion capsule 40 cosmonaut 40 Nicole Stott 40 commander Rick Sturckow 40 Stefanyshyn Piper 40 Space Shuttle 40 Schirra 39 space shuttle Atlantis 39 astronaut Sunita Williams 39 Soyuz rocket 39 Yurchikhin 39 Soyuz capsule 39 shuttle 39 Yuri Gagarin 39 shuttle Endeavour 39 lunar landing 39 Sunita Williams 39 human spaceflight 39 Shuttle Discovery 39 moon landings 38 Mission Specialists 38 Challenger 38 manned missions 38 Rick Husband 38 spacesuit 38 Dennis Tito 38 International Space Station 38 Tracy Caldwell Dyson 38 Linnehan 38 Space Shuttle Discovery 38 astronaut corps 38 Endeavour astronauts 38 shuttle astronauts 38 space shuttle Discovery 38 Russian Soyuz spacecraft 37 Hubble telescope 37 lunar missions 37 unmanned spacecraft 37 Gagarin 37 Space Shuttle Atlantis 37 solid rocket boosters 37 Malenchenko 37 Kennedy Space 37 space shuttles 37 space shuttle Endeavour 37 Atlantis astronauts 37 Shuttle Atlantis 37 orbiting laboratory 37 spacewalkers 37 lunar module 37 orbiting outpost 37 Neil Armstrong 37 Readdy 37 fighter pilot 37 orbiter 37 Hubble Space Telescope 36 Discovery astronauts 36 Soyuz TMA 36 Kopra 36 Astronaut 36 Shuttle Endeavour 36 Scaled Composites 36 rocketship 36 Mars rovers 36 orbital outpost 36 Nasa 36 Melroy 36 Eileen Collins 36 spacecrafts 36 Columbia Accident Investigation