She served as deputy undersecretary of defense for research and advance technology, as assistant secretary of energy for resource applications, and as chair of The Aerospace Corporation.

[1] At that time, Admiral Hyman G. Rickover was in search of computer programmers for his program to nuclearize the United States Navy, and unlike IBM, "didn’t care if you were yellow, purple, green, or had five arms".

He hired Davis among half a dozen other women, and in his service she was the first to write computer code for nuclear reactors.

[1] She also worked in the National Bureau of Standards as director of the Institute for Computer Sciences and Technology, and at the Department of Health, Education, and Welfare.

[2] She became deputy undersecretary of defense for research and advance technology from 1977 to 1979, when president Jimmy Carter appointed her as assistant secretary of energy for resource applications.