One of the most important events in the work-up of the Polaris submarines was the Demonstration and Shakedown Operation (DASO), which was conducted off Cape Kennedy in Florida. This operation culminated in the firing of a Polaris missile down the US Air Force Eastern Test Range to a target up to 2500 nautical miles away. The Ministry of Defence planned, in 1963, to fire Britain's first Polaris missile at 11.15 Eastern Standard Time on 15th February, 1968 - HMS Resolution failed to achieve this by just 15 milliseconds, but the firing was otherwise fully successful! Deterrent patrols began in 1969.
