Related by context. Frequent words. (Click for all words.) 57 Soviet cosmonaut Yuri Gagarin 53 NASA astronaut 51 Sally Ride 51 Anousheh Ansari 50 NASA Astronaut 50 Edwin Buzz Aldrin 49 astronaut 47 Yuri Gagarin 46 Alan Shepard 46 Eileen Collins 45 Dennis Tito 44 astronaut Peggy Whitson 43 Dan Tani 43 Kalpana Chawla 42 Daniel Tani 42 Japanese astronaut Koichi 41 Nichelle Nichols 41 Nicole Stott 41 Astronaut 41 Yang Liwei 41 Melroy 41 Mission Specialists 40 Buzz Aldrin 40 June Scobee Rodgers 40 sub orbital 40 ESA astronaut 40 shuttle Challenger 40 space shuttle 40 Piers Sellers 40 Christa McAuliffe backup 40 Satcher 40 astronaut Yang Liwei 40 Mercury Gemini 40 Mars Pathfinder 39 Peggy Whitson 39 Challenger exploded 39 Skylab 39 Megan McArthur 39 Soyuz spacecraft 39 Whitson 39 Sunita Williams 39 Space Shuttle 39 Caldwell Dyson 39 Christa McAuliffe 39 Paolo Nespoli 39 astronaut Sunita Williams 39 Doug Wheelock 39 Air Force colonel 38 Gagarin 38 Frank De Winne 38 shuttle 38 Space Shuttle Endeavour 38 Soyuz rocket 38 Cernan 38 Baikonur Kazakhstan 38 commander Peggy Whitson 38 Kotov 38 Michael Foale 38 Oleg Kotov 38 Leroy Chiao 38 Linnehan 38 cosmonaut 38 Russian Soyuz 38 spaceflights 37 Russian Soyuz spacecraft 37 Baikonur Cosmodrome 37 astronauts 37 Space Shuttle Discovery 37 spaceflight 37 spacewalker 37 unmanned lunar 37 Soyuz TMA 37 spacecraft 37 Soyuz 37 Sherpa Tenzing Norgay 37 teacher Christa McAuliffe 37 SpaceX Falcon 9 37 Systems Mission Directorate 37 Shuttle astronauts 37 Ilan Ramon 37 Soyuz craft 37 Fyodor Yurchikhin 36 Shuttle commander 36 Chiao 36 Robert Heinlein 36 Russian Soyuz rocket 36 Nie Haisheng 36 Cosmonaut 36 Greg Chamitoff 36 Women Airforce Service 36 manned spacecraft 36 Hobaugh 36 Kaguya 36 Malenchenko 36 Shuttle 36 NASA 36 Gregory Chamitoff 36 lunar orbiter 36 Robonaut 2 36 Gorie 36 orbit