1970 in spaceflight 1970 in spaceflight Japan and China each launched their first satellites in 1970, bringing the total number of nations with independent launch capability to five. Apollo 13 was launched; after suffering an explosion in deep space it had to circumnavigate the moon and use the LM as a life boat. Apollo 13 was a successful disaster in which the crew survived. The Soviet space program continued its Luna program with Luna 17, which delivered the robotic Lunokhod 1 rover to the lunar surface, and Luna 16, which achieved the first unmanned lunar sample return. The Soviets also continued the success
Apollo program landings. The S-IC first stage burned RP-1/LOX for a rated thrust of , which was upgraded to . The second and third stages burned liquid hydrogen, and the third stage was a modified version of the S-IVB, with thrust increased to and capability to restart the engine for translunar injection after reaching a parking orbit. NASA's Director of Flight Crew Operations during the Apollo program was Donald K. "Deke" Slayton, one of the original Mercury Seven astronauts who was medically grounded in September 1962 due to a heart murmur. Slayton was responsible for making all Gemini and Apollo crew assignments.