Alexander Henry Flax (January 18, 1921 – June 30, 2014) was the Chief Scientist of the U.S. Air Force (USAF) from 1959 to 1961, Assistant Secretary of the Air Force for Research and Development from 1963 to 1969, and the third Director of the National Reconnaissance Office (NRO) from 1965 to 1969. He was the director at a time when the second generation of imaging systems became operational and began to play a major role in United States intelligence during the Cold War. He oversaw major growth in NRO funding and personnel, the development of signals intelligence collectors from space, and the development of electro-optical imaging for US reconnaissance satellites.