The TV show The Americans, a cold-war drama set in Washington, DC, in the 1980s, features a robot that delivers mail and classified documents around the FBI office. That an autonomous vehicle existed in the 1980s might seem surprising. Marketed as the Mailmobile, it had first appeared a decade earlier.1
To guide the Mailmobile, a technician would lay out a chemical trail that gave off ultraviolet light from the mail room along the carpeted floors to various offices. The robot used a sensor to slowly follow the trail (at less than one mile per hour) until the chemical markings signaled it to stop. The Mailmobile cost between $10,000 and $12,000 (about $50,000 in today’s dollars), and for an extra fee, the company could attach ...