Edwin Aldrin earned his PhD from MIT in 1963 with a thesis titled, “Line-of-sight guidance techniques for manned orbital rendezvous”. Just three years later in 1966, Aldrin was the pilot of Gemini XII, the last flight of the Gemini program, a critical precursor to the Apollo moon program. Aldrin and his commander James Lovell were attempting to rendezvous and dock with an Agena target vehicle when their onboard radar failed. Aldrin used a handheld sextant to repeatedly measure the angles between Gemini XII and the Agena ahead and above them to help Lovell successfully complete the rendezvous and docking.
Aldrin would join Neil Armstrong and Michael Collins on the historic flight of Apollo 11 in 1969 — and later formally change his first name from “Edwin” to his other nickname “Buzz”.