George Johann Klein

I was young and full of beans. It was wonderful to have been at the lab because it was fun. Serious fun.” George Klein, commenting on his early years.

George Klein was a Canadian inventor who was not widely known in his home country until The Canadian Encyclopedia named him “the most productive inventor in Canada in the 20th century”. He was involved in the development of the robotic arm Canadarm used on the space shuttle and on the International Space Station.

George Johann Klein was born on August 15, 1904, in Hamilton, Ontario in Canada. His father had a watch and jewellery store, Klein and Binkley Jewellers in Hamilton and George probably acquired his early interest in mechanical design by watching his father at work in his workshop. Klein loved woodworking – he later helped students at the Crichton Street Elementary School in Ottawa with their woodwork projects – and built his own sailboat. He loved classical music and would become an accomplished violinist in the symphony orchestras of both Hamilton and Ottawa.

After graduating from the Hamilton Technical Institute High School Klein went to study at the University of Toronto where he graduated in 1928 with a Bachelor’s Degree in Applied Science - he never did a postgraduate study. When one of his professors, John H. Parkin, from the University of Toronto was appointed Director of Mechanical Engineering at the National Research Council (NRC) – Canada’s agency of scientific research and development – he called for his former student to join him. Klein joined the NRC in 1929 and stayed there for the next forty years.

Klein at the National Research Council

At the NRC George Klein was involved in many projects and he has been responsible for the design of the first wind tunnels at NRC. His experience in cross-country skiing had given him experience on snow and ice which helped him to develop plastic-coated skis for aircraft so they could land on snowy ground. This subsequently led to the development of a tracked snowmobile – the Weasel – which was manufactured for the U.S. Army as the M-29 Weasel by Studebaker. It was a small but fast troop-carrying tracked vehicle, specifically designed for transport across snow and ice, although it has been used equally successfully in the tropics. His expertise on the mechanics of snow was legendary and he was responsible for the development of an international system for classifying ground-cover snow. He also became an expert on gearing systems.

During World War II he headed the team that developed Canada’s first nuclear reactor, the Zero Energy Experimental Pile, which became operational in September 1945 – the first atomic reactor outside the United States. He also developed the first microsurgical staple gun used to successfully suture blood vessels. After the war he developed an electric wheelchair for quadriplegics to assist injured veterans of World War II both in Canada and the United States. The wheelchair was operated with a joystick and a drive system.

In the fifties he invented the STEM (Storable Tubular Extendible Member), an antenna rolled into a flat reel which could be unfolded on command. It saw its first application in space on the Canadian Alouette-1 satellite in 1962, and was soon adopted by NASA in its Mercury, Gemini and Apollo space projects. Its revolutionary design increased the size of satellite antennae from a few meters to more than 40 meters.

George Klein retired from NRC in 1969. After his retirement he served as adjunct professor at the Carleton University in Ottawa, Canada.

Canadarm in schematic form (left), extended in space (middle) and folded up in the
shuttle’s payload bay on the left (right). The arm seen on the Micronesia stamps is arm 301.


NASA launched its Space Shuttle program, officially called Space Transportation System (STS), in the early seventies, although it was conceived in the preceding decade. NASA had realized it needed a remote-controlled robotic arm to transfer payloads (initially satellites) from the shuttle’s payload bay to their intended position. The contract was awarded to a small group of Canadian high-tech companies (one of them being the manufacturer of the STEM antennae). The project would be managed by NRC which immediately called Klein out of retirement to act as consultant to the project for his expertise in industrial gearing systems. The Remote Manipulator System (RMS) would become known under its more popular name Canadarm.

Canadarm was a remote-controlled mechanical arm with a length of 15 meters and 38 cm in diameter. It had a total weight of just under 450 kg. Operating similar to a human arm, it had six joints: the shoulder with two joints for yaw and pitch, the elbow with one joint for pitch and the wrist with three joints for yaw, pitch and roll movement. The hand was formed by a wire-snare grappling device that fitted over a special grapple fixture on a payload. The joints had a gear ration between 739:1 and 1842:1 enabling it to maneuver payloads at speeds of up to 60 cm/s. The Canadarm was mounted at the shoulder in the shuttle’s payload bay. The mechanical arm had a camera at the wrist and an optional camera on the elbow as part of a closed-circuit tv system to enable an astronaut to manipulate the arm. One of the computers on board the shuttle was dedicated to the control of the arm. Although it could lift up to 266,000 kg in the weightlessness of space, it was unable to support its own weight in earth’s normal gravity.

Canadarm (301) had a work platform for astronauts to stand on when carrying out repairs to the Hubble Telescope.

Canadarm was first used in 1981 on board the Columbia during the STS-2 flight. Since then it has been used in more than 50 missions for a variety of tasks: launching new satellites, recovering lost satellites from space, two missions for critical repairs to the Hubble Space Telescope. After the Columbia disaster Canadarm was outfitted with an Orbiter Boom Sensor System to inspect (and repair if necessary) the shuttle’s exterior for damage. In all, five Canadarms have been built for NASA (arm 201, 202, 301, 302 and 303) with arm 302 being lost in the 1986 Challenger explosion.

On the left: Canadarm-2 with astronaut on foot restraint.
Middle: schematic drawing of Canadarm-2 to be attached to ISS during launch STS-8A.
Right: Installed at the ISS in space.


In 2001, the next version of Canadarm was launched – Canadarm-2, officially called the Space Station Remote Manipulator System. Its purpose was to assist space shuttles with docking at the International Space Station (ISS) and with assembly and maintenance of the ISS, moving equipment and supplies around the station and supporting astronauts when working in space around the ISS. Canadarm-2 was larger and more versatile than its predecessor with its seven joints, a length of 17.6m and a weight of 1,800 kg. It could relocate itself on the exterior of the ISS along a special track and reach its many parts. It received its power, data and video through the Power Data Grapple Fixtures positioned around the station’s exterior. Canadarm-2 was controlled with two joysticks and three robotic work station LCD screens.

The intricate robotic operation of passing payloads from the shuttle’s Canadarm to the ISS’ Canadarm-2 for installation at the ISS was soon dubbed the “Canadian Handshake” by the media.

Dextre is shown in the bottom of this Canadian stamp.

The Special Purpose Dexterous Manipulator, or Canadarm-2’s hand, also known as “Dextre”, was added to Canadarm-2 in 2008. This sophisticated two-armed robot has two agile 3m long arms, each with their own built-in grasping jaws, attached to a 3.5m long headless body that pivots at the waist. It has its own sets of tv cameras and carries a tool holster containing a variety of tools. It is mainly used for small delicate service tasks on the ISS’ exterior which had previously required space walks.

The “Canadian Handshake” in action in 2001:
Canadarm-2 on the ISS transfers its launching cradle to Canadarm-1 on
the shuttle Endeavour. The whole operation was controlled by Canadian
astronaut Chris Hadfield (second stamp in the right-hand column).

George Klein honoured

George Klein, who passed away on November 4, 1992, at the age of 88 in Ottawa, Ontario, Canada, has been awarded a number of honorary doctorates.
In 1968, he was made an Officer of the Order of Canada.
He was also made a Member of the Order of the British Empire.
In 1995, he was posthumously inducted to the Canadian Science and Engineering Hall of Fame.
In 1996, the Carleton University in Ottawa established the George Klein Medal as overall prize for high school students participating in an industrial design competition.

In 2000, Canada honoured this brilliant inventor by portraying him on a stamp in its Millennium Series against a background of several gear wheels – his speciality. Another stamp in the same series was dedicated to the Canadian Space Program and shows the two-armed Dextre. The two robotic arms Canadarm-1 and Canadarm-2 have been featured on a number of stamps from several countries.

© Wobbe Vegter, 2009

[ Back ]