Regulus 1 missile mail container
On June 8, 1959, the U.S. Navy fired a Regulus I missile from the USS Barbero submarine and directed it to land at the Naval Auxiliary Air Station at Mayport, Florida, near Jacksonville. This container, along with a second container, was placed inside the missile prior to the flight. Together the two held 3,000 letters.
The metal containers were painted red and blue, the colors used at the time for mail boxes, and marked "US Mail." Postmaster General Arthur Summerfield posed for photographers as he helped place mail inside these containers. The missile was fired from the submarine shortly before noon and arrived at Mayport twenty-two minutes later.
Ostensibly an experiment in communication transportation, the Regulus’s mail flight sent a subtle signal that, in the midst of the Cold War, the U.S. military was capable of such accuracy in missile flight that it could be considered for use by the post office. The missile employed a then state-of-the-art guidance system that could precisely deliver a thermonuclear weapon from a distance of six hundred miles. The trip from the USS Barbero to Mayport was only one hundred miles in distance, but it helped to illustrate another possible use for the weapons technology. The space used for the containers was space that was originally designed to hold the missile’s nuclear warhead.
Postmaster General Summerfield was ecstatic over the possibilities of postal uses for the technology, claiming that “This peacetime employment of a guided missile for the important and practical purpose of carrying mail is the first known official use of missiles by any post office department of any nation. Before man reaches the moon, mail will be delivered within hours from New York to California, to Britain, to India or Australia by guided missiles.” Summerfield’s enthusiasm notwithstanding, the 1959 USS Barbero test firing was the only incidence of using a missile to carry mail in the United States.
Press releases, Third Assistant Postmaster General files, NPM