AUTODIN (Automatic Digital Network) Service, in the context of aviation and aerospace, refers to a system used by the United States Department of Defense (DoD) for the transmission of digital messages, including those related to flight planning, air traffic control, and weather information.

AUTODIN is a high-speed, store-and-forward message switching system that was initially developed in the 1950s for use by the US military. In the context of aviation and aerospace, AUTODIN is used to facilitate the exchange of critical information between air traffic control centers, weather services, and other aviation stakeholders.

The AUTODIN system is used to transmit a variety of messages, including:

1. Flight plans: AUTODIN is used to transmit flight plans from airlines and other operators to air traffic control centers.
2. Weather information: AUTODIN is used to disseminate weather forecasts, warnings, and other meteorological information to pilots and air traffic controllers.
3. NOTAMs (Notices to Airmen): AUTODIN is used to transmit NOTAMs, which provide critical information about airspace restrictions, hazards, and other conditions that may affect flight operations.
4. Air traffic control messages: AUTODIN is used to transmit messages between air traffic control centers, including clearance, instruction, and advisory messages.

The AUTODIN system has been largely replaced by more modern systems, such as the Federal Aviation Administration's (FAA) Automated Flight Service Stations (AFSS) and the International Civil Aviation Organization's (ICAO) Aeronautical Fixed Telecommunication Network (AFTN). However, AUTODIN is still used in some parts of the world, particularly in areas where more modern systems are not available.