US Navy submarine launched missile carrying 3,000 letters in 1959
The 22-minute flight from a submarine to Florida was intended to demonstrate how military technology could serve civilian purposes.
A US Navy submarine launched a guided missile containing 3,000 letters towards Florida on June 8, 1959, according to a report by the Times of India. The Regulus I cruise missile was fired from the USS Barbero and reached the Naval Auxiliary Air Station at Mayport near Jacksonville in 22 minutes.
The missile travelled approximately 100 miles to its destination. Two metal containers, painted red and blue to resemble American postal boxes, were placed in the section of the missile typically used for nuclear payloads.
US Postmaster General Arthur Summerfield participated in the operation, which was presented as a way to explore faster methods for moving correspondence. Summerfield stated that this was the first time a national postal department had officially used a guided missile to transport mail.
Summerfield predicted that guided missiles could eventually deliver letters between New York and California, or to countries such as India, Britain and Australia, in just a few hours. He suggested this could happen before humans reached the Moon.
Despite the successful flight, the experiment never became a regular postal service. The June 1959 launch remains the only known instance of the US Postal Service using a guided missile for mail delivery.
The Smithsonian National Postal Museum currently holds a container from the demonstration to document the attempt to use military technology for civilian mail transport.
