Capsule communicator

During much of the U.S. manned space program, NASA felt it was important for all normal communication with the astronauts in space to pass through a single individual in the Mission Control Center. That role was designated the capsule communicator or capcom and was typiclly filled by another astronaut, often one of the backup crew members. For long duration missions, there would be more than one capcom, each assigned to a different shift team. After control of U.S. spaceflights moved to the Lyndon B. Johnson Space Center in the early 1960s, capcoms used the radio callsign Houston.