As a Naval Aviator, he flew 78 combat missions from an aircraft carrier. Mr. Armstrong subsequently served 17 years with the NACA and NASA as an engineer, test pilot, astronaut and administrator.

As a research pilot at NASA's Flight Research Center at Edwards, California, he was a project pilot on many pioneering high speed aircraft, including most of the early supersonic jets, the rocket powered X-1, the variable sweep wing X-5, the vertical take off and landing X-14, and the well known X-15, which he flew to over 200,000 feet altitude and Mach 5.74.
He transferred to astronaut status in 1962. He was the commander of the Gemini 8 flight in 1966 when he performed the first successful docking of two vehicles in space. As spacecraft commander for Apollo 11, he, with colleagues Mike Collins and Buzz Aldrin, completed the first landing mission to the moon.

He has been holder of 13 world records in aviation and space.

He received his engineering degrees from Purdue University and the University of Southern California. During the years 1971-1979, he was Professor of Aerospace Engineering at the University of Cincinnati. He is a member of the U. S. National Academy of Engineering and the Royal Academy of the Kingdom of Morocco.