The conceptual design for this mission was first proposed by an MIT professor, George Pugh, who was working with the U.S. Department of Defense in <time>1959</time> and later discussed by Leonard Schiff (Stanford) in <time>1960</time> at Pugh's suggestion, based partly on a theoretical paper about detecting frame dragging that Schiff had written in <time>1957</time>. It was proposed to NASA in <time>1961</time>, and they supported the project with funds in <time>1964</time>. This grant ended in <time>1977</time> after a long phase of engineering research into the basic requirements and tools for the satellite.