‘‘Canadarm’’ is the remote manipulator system (RMS) given by Canada to NASA for installation on the shuttle orbiter. The RMS is to be used for deployment, retrieval, and handling of payloads up to 65 000 lb mass, 15 ft in diameter and 60 ft in length. Controllability, operating constraints, flight environments, safety, reliability, volume, weight, and power allocations were factors which influenced the design. The system uses brushless dc servomotors to drive the six joints and the end effector of the 50 ft arm in a variety of control modes, which provide both manual and automatic control of arm functions. In describing the system, this paper concentrates on the various mechanical devices which are required to operate in the orbital environment and discusses some of the problems encountered during their development. SPAR Aerospace Ltd., under contract to the National Research Council of Canada, designed, developed, manufactured, tested, and delivered the system, which at the time of this writing has been successfully demonstrated on two flights of the orbiter ‘‘Columbia.’’