Technical research ships were used by the United States Navy during the 1960s to gather intelligence by monitoring, recording and analyzing wireless electronic communications of nations in various parts of the world. At the time these ships were active, the mission of the ships was covert and discussion of the true mission was prohibited ("classified information"). The mission of the ships was publicly given as conducting research into atmospheric and communications phenomena. However, the true mission was more or less an open secret and the ships were commonly referred to as "spy ships". Function These ships carried a crew of U.S. Navy personnel whose specialty was intercepting wireless electronic communications and gathering intelligence from those communications (signals intelligence, communications intelligence, and electronic signals intelligence (SIGINT)). In the 1960s those personnel had a U.S. Navy rating of Communications Technician (later changed to Cryptologic Technician), or CT. In order to transmit intelligence information that had been gathered back to United States for further processing and analysis, these ships had a special system named Technical Research Ship Special Communications, or TRSSCOM (pronounced tress-com). This Earth-Moon-Earth (EME) communications system used a special gyroscope-stabilized parabolic antenna, which can be seen aft of the main superstructure in the accompanying photographs of Belmont and Liberty. Radio signals were transmitted toward the moon, where they would bounce back toward the Earth and be received by a large parabolic antenna at a Naval Communications Station in Cheltenham, Maryland (near Washington, D.C.) or Wahiawa, Hawaii. Communications could occur only when the moon was visible simultaneously at the ship's location and in Cheltenham or Wahiawa. The gyro stabilization of the antenna kept the antenna pointed at the moon while the ship rolled and pitched on the surface of the ocean. These ships were classified as naval auxiliaries with a hull designation of AGTR, which stands for Auxiliary, General, Technical Research. Five of these ships were built with hull numbers of 1–5. The first three ships of this type (Oxford, Georgetown, and Jamestown) were converted from World War II-era Liberty ships. The last two ships (Belmont and Liberty) were converted from Victory ships. The former Liberty ships' top speed of limited the first three AGTRs to missions of slow steaming on station with a minimum of transits. Victory ships' sustained speed of enabled Belmont to shadow Mediterranean Sea operations of the Soviet helicopter carrier in 1969. All of the technical research ships