Between the years 1957 and 1958, U.S. President Dwight D. Eisenhower sought cooperative U.S.-Soviet space initiatives through a series of letters directed at Soviet leadership. These Soviet recipients included Premier Nikita Khrushchev and Prime Minister Nikolai Bulganin. In these letters, Eisenhower suggested a protocol for peaceful space use. However, Khrushchev rejected the offer, feeling that his country was ahead of the United States in space-related technology after the successful launch of Sputnik 1 on October 4, 1957. In response, Khrushchev presented a precondition for any future space agreements. Khrushchev demanded that the United States would first need to remove its nuclear-launch capabilities in Turkey. This signaled a future trend of space agreements as a means for nuclear disarmament.