The Freedom 7 spacecraft, Mercury capsule #7, was delivered to Cape Canaveral on December 9, 1960. It had originally been expected that a mission could be launched soon after the spacecraft was available, but Capsule #7 turned out to require extensive development and testing work before it was deemed safe for flight. However, as it had been earmarked since the summer as the first crewed spacecraft, the decision was taken to delay the mission until this particular capsule was ready, with a tentative launch date of March 6, rather than use an alternative capsule. The booster originally intended for the flight, Redstone #3, had been delivered to the Cape in early December; however, it was then used on the MR-1A test flight on December 19. The replacement, Redstone #7, did not arrive at the Cape until late March; by this time, however, the mission had already been postponed to await the results of another test flight.