Related by context. Frequent words. (Click for all words.) 51 shuttle Challenger 47 teacher Christa McAuliffe 47 Challenger exploded 45 space shuttle 44 Alexander Kaleri 44 Christa McAuliffe backup 43 Mission Specialists 43 NASA astronaut 42 Russian cosmonaut Yuri Malenchenko 42 Christa McAuliffe 42 Space Shuttle Columbia 42 lunar module 42 crewmembers aboard 42 Ilan Ramon 42 astronaut 42 NASA astronaut corps 42 Shuttle astronauts 41 Daniel Hoover Najera 41 Fyodor Yurchikhin 40 Soviet cosmonaut Yuri Gagarin 40 Bulava missile 40 Oleg Skripochka 40 crewmates 40 astronauts 40 Kalpana Chawla 40 Astronaut 40 shuttle disintegrated 40 By Gina Gallucci 40 Israeli astronaut Ilan 39 Space Shuttle Discovery 39 crewmate 39 Mikhail Kornienko 39 Space Shuttle 39 Piers Sellers 39 Gagarin 39 Baikonur Kazakhstan 38 Sputnik satellite 38 Skylab 38 Ares IX rocket 38 NASA Astronaut 38 Apollo astronauts 38 Challenger 38 crewmen aboard 38 Launch Vehicle 38 Space Shuttle Endeavour 38 Pablo Cerda 38 ISS Expedition 38 Soyuz TMA 38 F/A-#C Hornet 38 SpaceX Falcon 9 38 space shuttle Endeavour 38 shuttle missions 37 June Scobee Rodgers 37 Khe Sahn 37 Russian Soyuz TMA 37 Tim Kopra 37 satellite Sputnik 37 crewmen 37 astronauts aboard 37 spacecraft 37 Gagarin flight 37 liftoff 37 Discovery STS 37 Japanese astronaut Soichi 37 Michael Foale 37 Discovery liftoff 37 lunar landing 36 Space Shuttle Challenger 36 Apollo 36 crewmembers 36 NEEMO 36 Flight Engineer 36 Space Shuttle Atlantis 36 thrusters 36 Orion spacecraft 36 orbiter 36 Mars Lander 36 Hubble servicing 36 Launch Pad #B 36 Eugene Cernan 36 shuttle Endeavour 35 Soyuz capsule 35 administrator Sean O'Keefe 35 Rick Husband 35 blastoff 35 NASA Administrator 35 Shuttle Endeavour 35 Chinook crashed 35 Yuri Gagarin 35 Eileen Collins 35 Soyuz craft 35 pad #A 35 Caldwell Dyson 35 perished 35 resupply mission 35 Schirra 35 Taurus XL rocket 35 spaceship 35 Shuttle Atlantis 35 spaceplane 35 Cape Canaveral Fla.