Robert D Cowan received his undergraduate degree from Friends University (FU) in Wichita, Kansas, and pursued a doctorate in physics at John Hopkins University (1946). He met his wife, Dorothy, in 1944 at FU and they moved to Chicago for Cowan to do postdoctoral research at the University of Chicago. In 1951, the family moved to Los Alamos, NM, where Cowan began his career at Los Alamos Scientific (later National) Laboratory (LANL). Cowan worked there until his retirement in 1985.

Cowan was a Fellow of the American Physical Society, The Optical Society, and LANL. Other recognitions included an honorary doctorate from Lund University (1982), the Los Alamos Medal (2008), and the OSA William F. Meggers Award (1984) for his world-recognized contributions to the theory of atomic structure and spectra. Cowan published more than 120 papers and was the author of The Theory of Atomic Structure and Spectra (1981).

Cowan passed away in 2018.