An astronaut is a person trained by a human spaceflight program like NASA to serve as a commander or crew member on space missions. NASA is the U.S. government agency responsible for aerospace research and technology, including overseeing space exploration efforts. NASA was created in 1958 in response to the Soviet Union launching Sputnik and is led by an administrator appointed by the president. Moon landing sites from Apollo missions can still be seen with powerful telescopes, providing evidence that astronauts did in fact reach the moon.