Since October 1959, when a nuclear-armed Atlas D missile first went on alert, ICBMs have protected the nation. This month marks the 50th anniversary of the ICBM. Shown here is a Minuteman III with a single unarmed re-entry vehicle successfully test launching from Vandenberg Air Force Base, Calif. The RV traveled approximately 4,190 miles to a pre-determined target near the Kwajalein Atoll in the Marshall Islands. (U.S. Air Force photo/Joe Davila)