On October 21, 1959, Eisenhower approved the transfer of the Army's remaining space-related activities to NASA. On July 1, 1960, the Redstone Arsenal became NASA's George C. Marshall Space Flight Center, with von Braun as its first director. Development of the Saturn rocket family, which when mature, would finally give the US parity with the Soviets in terms of lifting capability, was thus transferred to NASA.
The Redstone Arsenal became the George C. Marshall Space Flight Center when? (If the question is unanswerable, say "unanswerable")
July 1, 1960