Related by context. Frequent words. (Click for all words.) 61 Metcalf Lindenburger 57 NASA astronaut 56 astronaut 56 Piers Sellers 56 Tim Kopra 55 Astronaut 53 NASA Astronaut 52 Christa McAuliffe backup 52 Christa McAuliffe 52 Nicole Stott 52 Julie Payette 52 Leland Melvin 52 Greg Chamitoff 51 Discovery STS 50 NASA astronaut corps 50 Koichi Wakata 50 Soviet cosmonaut Yuri Gagarin 49 Alexander Kaleri 49 Space Shuttle Endeavour 49 ESA astronaut 49 space shuttle 49 Gregory Chamitoff 48 teacher Christa McAuliffe 48 Peggy Whitson 48 Shuttle astronauts 48 Frank De Winne 48 Shuttle Discovery 48 NEEMO 48 Acaba 47 Kalpana Chawla 47 Russian cosmonaut Yuri Malenchenko 47 Megan McArthur 47 Dan Tani 47 Bob Thirsk 47 NASA 46 Joan Higginbotham 46 Sandra Magnus 46 aboard Endeavour 46 shuttle Atlantis 46 Japanese astronaut Koichi 46 Scott Parazynski 46 Virts 46 Space Shuttle Discovery 46 astronaut Sunita Williams 45 International Space Station 45 Mission Specialists 45 Apollo lunar 45 astronauts 45 space shuttle Discovery 45 Rex Walheim 45 cosmonaut 45 Zamka 45 shuttle 45 Space Shuttle 45 astronaut corps 45 Shuttle Endeavour 45 astronaut Julie Payette 45 Ilan Ramon 45 NASA Kepler 44 shuttle Discovery 44 Andrew Feustel 44 De Winne 44 space shuttle Endeavour 44 astronaut Roberto Vittori 44 Challenger exploded 44 Paolo Nespoli 44 Endeavour 44 Space Shuttle Atlantis 44 Eileen Collins 44 Lee Archambault 44 NASA Space Shuttle 44 astronaut Yang Liwei 43 Mikhail Tyurin 43 Gagarin 43 Nie Haisheng 43 shuttle Challenger 43 Daniel Tani 43 Donald Pettit 43 Nasa 43 shuttle missions 43 Oleg Kononenko 43 Caldwell Dyson 43 Eyharts 43 Astronaut Buzz Aldrin 43 Hoshide 43 shuttle Endeavour 43 Space shuttle Endeavour 43 SpaceX Falcon 9 42 Astronauts 42 Oleg Skripochka 42 Flight Engineer 42 Fossum 42 phys ed teacher 42 Mars Pathfinder 42 spaceflight 42 ARISS 42 Microgravity 42 Tracy Caldwell Dyson 42 astronaut Leopold Eyharts 42 Shuttle Atlantis 42 Romanenko