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,
Space rendezvous maneuvering thrusters to adjust its orbit to match that of its twin. The initial separation distances were in the range of , and slowly diverged to thousands of kilometers (over a thousand miles) over the course of the missions. In 1963 Buzz Aldrin submitted his doctoral thesis titled, " Line-Of-Sight Guidance Techniques For Manned Orbital Rendezvous." As a NASA astronaut, Aldrin worked to "translate complex orbital mechanics into relatively simple flight plans for my colleagues." The first attempt at rendezvous was made on June 3, 1965, when US astronaut Jim McDivitt tried to maneuver his Gemini 4 craft to meet