Table of Contents

The Development of a Legend

The challenge to industry and government

Canadarm originated in a technical challenge issued by NASA in the early seventies for its new Space Transportation System that we now know as the Space Shuttle. In June 1969, a month before the Apollo astronauts stepped onto the Moon, design studies of the various shuttle system components were presented to a number of countries, including Canada.

Meanwhile, DSMA Atcon, a small Canadian firm, had got NASA's attention with a robot they had developed to load fuel into a nuclear reactor. Together with Spar, CAE Electronic, and RCA (later Spar Montreal), they drafted a proposal for a remote manipulator system, a robotic arm that could deploy and retrieve space hardware from the payload bay of the orbiter. Although NASA was interested, money was scarce for such a high-risk program.

With the support of Jeanne Sauvé, then Minister of State for Science and Technology, the project was launched and, in 1974, Canada agreed to build the first Shuttle Remote Manipulator System. Spar, CAE and DSMA Atcon formed the industrial team, with the National Research Council of Canada (NRC) to oversee the project. It would be Canada's contribution to NASA' shuttle project.

Design constraints

In the early 1970s, Spar, carried out design studies for a type of manipulator and was appointed the prime subcontractor to the NRC in July of 1975 for the design development, testing, and evaluation of the manipulator arm system. The challenge facing the design team was enormous.

There were no existing blueprints or off-the-shelf components for machines that work continually in the harsh environment of space. NASA had stringent demands for weight, dexterity, manual and automatic operations, versatility, precision of movement, safety, and reliability. From scratch, Canada had to build a tool to function flawlessly in space with the dexterity of a human arm.

To stand up to the harsh environment of space, Canadarm needed the latest in aerospace materials, including titanium, stainless steel, and graphite epoxy. It would need an insulated blanket with thermostatically controlled heaters to maintain an acceptable temperature in space.

The magnificent result

With nerves of copper wiring, bones of graphite fibre, and electric motors for muscles, Canadarm is like the human arm. It has rotating joints: two at the shoulder, one at the elbow and three at the wrist. At 15 metres and weighing less than 480 kilograms, Canadarm can lift over 30,000 kilograms-up to 266,000 kg in the weightlessness of space–or the mass of a fully loaded bus, using less electricity than a teakettle.

The brain of the system is a computer that controls the arm while providing essential guidance information to the astronaut. It can be operated manually by an astronaut at the controls or programmed to function automatically. Its hand is a wire-snare device that fits over a special grapple fixture on the payload.

Testing

Designing and building the robotic device were difficult enough but testing the final product proved to be even more challenging. Meant for a weightless environment, Canadarm cannot even lift itself off the ground in Earth's gravity. A special test room was built to allow the arm to flex its joints under operating conditions. In addition, a computer-based simulation facility, much like a video game, was built to evaluate controllability and provide training for astronauts.

Investment

The Government of Canada invested $108 million in designing, building, and testing the first Canadarm flight hardware, which was given to NASA for the orbiter Columbia. NASA bought four more robotic arms from the industry team, now MDA. The Government of Canada's original investment resulted in nearly $700 million in export sales. Ongoing maintenance and engineering support add approximately $20 million annually.