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Canadarm, the first robotic manipulator system designed specifically for use in space, made its first appearance on STS-2.

Canadarm deploys for the first time (NASA)

The real name for the Canadarm is the Shuttle Remote Manipulator System, or SRMS.

Canadarm was developed by the National Research Council of Canada, a Canadian industrial team composed of DSMA Atcon, Spar, and CAE Electronic. Development began in 1974. Spar was appointed the prime subcontractor in July 1975.

The arm is designed to work like the human arm, with two rotating joints at the shoulder, one at the elbow, and three at the wrist. At 15 meters in length, it can lift over 30,000 kilograms. The control system provides precision control of the movements of the arm.

Canada built five Canadarms for NASA. Arm 201 was delivered in April 1981, arm 202 in January 1983, arm 301 in December 1983, arm 302 in March 1985, and arm 303 in August 1993. Arm 302 was destroyed aboard the Challenger (51-L) in 1985. The first use was of arm 201 was aboard Columbia flight STS-2. The Canadarm was retired with the final shuttle flight STS-135 (Discovery). Arm 201 (taken from Endeavour) is now on display at the Canada Aviation and Space Museum in Ottowa, Ontario. Discovery's arm is now on display next to Discovery at the Smithsonian National Air and Space Museum's Steven F. Udar-Hazy Center in Virginia. Another arm, taken from Atlantis, was sent to Houston for study and possible reuse in the future. After the Columbia tragedy, one arm had parts used to construct an extension (OBSS - Orbiter Boom Sensor System) to inspect the shuttle heat shield in flight. The OBSS was left at the ISS to extend the reach of the Canadarm2.

Originally, the Canadarm was used to launch, retrieve, and repair satellites from the space shuttle. It has also been used in Hubble repairs. Later, it aided in construction of the ISS. Since the Columbia disaster, every shuttle flight carried a Canadarm. An inspection boom extension and laser camera system (OBSS) were added so that a complete inspection of the shuttle could be performed and, if needed, repairs made.

After the capture of Intelsat VI during STS-49 (NASA)

With the success of Canadarm, Canadarm2 was built for the ISS and installed during STS-100.

Canadarm and Canadarm2 - Comparative Table

Installed on each shuttle and returns to Earth.
Only one installed on the International Space Station and stays permanently in space.
Range of Motion
Reach limited to length of arm.
Moves end-over-end to reach many parts of International Space Station limited only by number of Power Date Grapple Fixtures on the Station (PDGF). PDGFs located around the Station provide power, data and video to the arm through its Latching End Effectors (LEE). The arm can also travel the entire length of the Space Station on the Mobile Base System.
Fixed joint
Fixed to the shuttle by one end.
No fixed end. Equipped with LEEs at each end.
Degrees of freedom
6 degrees of freedom. Similar to a human arm: shoulder (2 joints), elbow (1 joint), and wrist (3 joints).
7 degrees of freedom. Much like a human arm: shoulder (3 joints), elbow (1 joint), wrist (3 joints). However Canadarm2 can change configuration without moving its hands.
Joint rotation
Limited elbow rotation (to 160 degrees).
Full joint rotation. Joints (7) rotate 540 degrees. Larger range of motion than a human arm.
No sense of touch
Force movement sensors provide a sense of "touch." Automatic vision feature for capturing free-flying payloads. Automatic collision avoidance.
15 metres
17 metres
410 kg
1,641 kg
33 cm (Ext. Diameter of Composite Boom)
35 cm (Ext. Diameter of Composite Boom)
Speed of Operations
Unloaded: 60 cm/sec
Loaded: 6 cm/sec
Unloaded: 37 cm/sec
Loaded: 2 cm/sec Station assembly 2 cm/sec.; EVA support: 15 cm/sec.; Orbiter: 1.2 cm/sec
16 plies of high modulus carbon fibre−epoxy
19 plies of high strength carbon fibre−thermoplastic
Repaired on Earth.
Designed to be repaired in space with ORUs (Orbital Replacement Units). Built-in redundancy.
Autonomous operation or astronaut control
Autonomous operation or astronaut control
2 (one on the elbow and one on the wrist)
4 colour cameras (one at each side of the elbow, the other two on the LEEs)

(From the Canadian Space Agency)


Page last modified: 05 November 2023 09:38:38.