 The Program 437 mission was approved for development by U.S. Secretary of Defense Robert McNamara on November 20, 1962 and based at the Atoll.Program 437 used modified Thor missiles that had been returned from deployment in Great Britain and was the second deployed U.S. operational nuclear anti-satellite operation.Eighteen more suborbital Thor launches took place from Johnston Island during the 1964–1975 period in support of Program 437.