He was the Principal Investigator (PI) for the Apollo 11 laser ranging retro-reflector (LR3) experiment,[4] deployed on the moon by Neil Armstrong and Buzz Aldrin in 1969.
In addition to the gravitational interaction results mentioned above, the experiment measured the orbit of the moon to centimeter accuracy—and still produces data to this day.
[6] Some additional accomplishments of Professor Alley, his graduate students, the Quantum Electronics Research and Lunar Ranging Experiment Teams, support staff, and numerous collaborators include:[6] In later years Alley collaborated in the study, development, and application of a new formulation of gravity as curved spacetime[7] found by Professor Huseyin Yilmaz.
Alley attended John Marshall High School, where he was a swimmer, choir member, and Cadet Corps First Captain and Regimental Commander of A Company.
From 1954 to 1960, he was an instructor and lecturer in both Electrical Engineering and Physics[10] at Princeton, where he met and married his late wife, Elizabeth (Slack) Delany Alley.
His PhD dissertation developed new methods of detecting the ground state hyperfine transition in optically-pumped rubidium vapor for the type of atomic clock invented by Princeton professors Robert Henry Dicke—Alley’s thesis advisor—and Thomas R. Carver.
In 1963 Alley was recruited to the University of Maryland, College Park Campus, by John S. Toll, then-chair of the Department of Physics and Astronomy.