1973: ARPANET goes international

In 1973, the ARPANET became international, with a satellite link connecting Norway and London to the other nodes in the United States. Hawaii also joined the network by satellite. At this point, the network had around 40 nodes. New ARPANET applications had begun to emerge. Email was invented in 1971 by a BBN engineer named Ray Tomlinson, who also invented the use of the "@" symbol in email addresses. The File Transfer Protocol, which is still used today, allowed ARPANET users to send files to each other.