Formed in 1958 in response to the successful Soviet launch of the Sputnik satellite into space, national defense department agency DARPA (Defense Advanced Research Projects Agency) has been responsible for research into breakthrough, though often highly speculative military technology. The Eisenhower administration implemented ARPA with three concrete goals: to get us into space, protect us from Soviet missile attacks, and develop technology to detect Soviet nuclear tests. As a national security agency, DARPA has been funded entirely by taxpayer money.
Aisha Sohail (2010) studied this question.