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Meeting New Needs

Evolving and adapting the technology

Although it still shares common elements with the original design, Canadarm has changed a lot since its launch in 1981, and adaptations have been made continually. These are based on performance in the space environment and on new operational requirements. The Shuttle arm has undergone numerous hardware changes, and has seen improvements in manufacturing processes and transformations to the control software. Canadarm's versatility has become more evident as it meets new operational requirements.

Canadarm on Space Shuttle Atlantis during mission STS-74 in 1995. It was Chris Hadfield's first space flight. (Photo: NASA)

The technology has evolved over the years, with improvements to make trajectory control more accurate and to provide more precise control at low speeds. Also, there have been refinements to the positioning and force capabilities, the ability to backdrive the arm, and the command and display capabilities.

Canadarm is now used for some assembly tasks of the International Space Station. It helps connect large mass elements with a variety of interface systems that are not like those normally used for Shuttle cargo payload deployment and retrieval.

Canadarm: Safety Inspector

Following the Columbia accident in 2003, NASA mandated changes for the Shuttle program to improve security. Inspections of the underside of the Shuttle before reentry are now required.

MDA thus developed an extension to Canadarm to perform these on-orbit inspections of the Shuttle's thermal protection system. At the end of this new extension boom are two cameras. One is a Laser Camera System built by Neptec of Ottawa. Now the arm can inspect even hard-to-reach areas on the underside of the spacecraft that cannot normally be viewed from the Shuttle.

Nobody could have anticipated the visibility and pride that the Canadarm would generate for Canadian space technology. Whenever the arm is observed through the aft window of the Shuttle's crew cabin, the source of this pride is evident.