Buzz Aldrin shot down two MiG-15 aircraft. After earning a Sc.D. degree in astronautics from the Massachusetts Institute of Technology, Aldrin was selected as a member of NASA's Astronaut Group 3, making him the first astronaut with a doctoral degree. His doctoral thesis was "Line-of-Sight Guidance Techniques for Manned Orbital Rendezvous", earning him the nickname "Dr. Rendezvous" from fellow astronauts. His first space flight was Gemini 12 during which he spent over five hours on extravehicular activity (EVA) outside the spacecraft. Aldrin set foot on the Moon at 03:15:16 on July 21, 1969 (UTC), nine minutes after Armstrong first touched the surface,
Buzz Aldrin Pilot as the first to step onto the lunar surface. However, when Aldrin learned that this might be amended, he lobbied within NASA for the original procedure to be followed. Multiple factors contributed to the final decision, including the physical positioning of the astronauts within the compact lunar lander, which made it easier for Armstrong to be the first to exit the spacecraft. Furthermore, there was little support for Aldrin's views among other senior astronauts who would command later Apollo missions, and who may have been the first to make a lunar landing had Apollo 11 failed. Collins has commented