Computer systems and people professionals that maintain, troubleshoot, program, administer, community, and construct them are central to most every trade. The US Military asked Bell Laboratories to design a machine to assist in testing its M-9 gun director, a type of analog laptop that aims giant guns to their targets. Mathematician George Stibitz recommends using a relay-based calculator for the mission. The consequence was the Relay Interpolator, later known as the Bell Labs Mannequin II. The Relay Interpolator used 440 relays, and because it was programmable by paper tape, was used for other purposes following the war.