Secord, Meagher and Associates, Ltd. in Toronto was contracted to produce the engineering model end effector then SPAR evolved the design and produced the qualification and flight units. The Space Shuttle flight software that monitors and controls the Canadarm was developed in Houston, Texas, by the Federal Systems Division of IBM. Rockwell International's Space Transportation Systems Division designed, developed, tested, and built the systems used to attach the Canadarm to the payload bay of the orbiter. An acceptance ceremony for NASA was held at Spar's RMS Division in Toronto on 11 February 1981. Here Larkin Kerwin, then the head of the NRC, gave the SRMS the informal name, Canadarm. The first Canadarm was delivered to NASA in April 1981. Astronaut Judith Resnik developed the NASA software and onboard operating procedures for the system. In all, five arms – Nos. 201, 202, 301, 302, and 303 – were built and delivered to NASA. Arm 302 was lost in the Challenger accident. Design and capabilities The original Canadarm was capable of deploying payloads weighing up to in space. In the mid-1990s, the arm control system was redesigned to increase the payload capability to in order to support space station assembly operations. While able to maneuver payloads with the mass of a loaded bus in space, the arm motors cannot lift the arm's own weight when on the ground. NASA, therefore, developed a model of the arm for use at its training facility within the Johnson Space Center located in Houston, Texas. The Canadarm can also retrieve, repair and deploy satellites, provide a mobile extension ladder for extravehicular activity crew members for work stations or foot restraints, and be used as an inspection aid to allow the flight crew members to view the orbiter's or payload's surfaces through a television camera on the Canadarm. The basic Canadarm configuration consists of a manipulator arm, a Canadarm display, and a control panel, including rotational and translational hand controllers at the orbiter aft flight deck flight crew station, and a manipulator controller interface unit that interfaces with the orbiter computer. One crew member operates the Canadarm from the aft flight deck control station, and a second crew member usually assists with television camera operations. This allows the Canadarm operator to view Canadarm operations through the aft flight deck payload and overhead windows and through the closed-circuit television monitors at the aft flight deck station. The Canadarm