The Shuttle Remote Manipulator System (SRMS), also known as Canadarm (Canadarm-1), is a series of robotic arms that were used on the Space Shuttle orbiters to deploy, maneuver and capture payloads. After the Space Shuttle Columbia disaster, the Canadarm was always paired with the Orbiter Boom Sensor System (OBSS), which was used to inspect the exterior of the Shuttle for damage to the thermal protection system.
The Canadarm was seen in Gravity.
Development[edit | edit source]
In 1969, Canada was invited by the American National Aeronautics and Space Administration (NASA) to participate in the Space Shuttle program. At the time what that participation would entail had not yet been decided but a manipulator system was identified as an important component. Canadian company, DSMA Atcon, had developed a robot to load fuel into CANDU nuclear reactors, this robot attracted NASA's attention. In 1975, NASA and the Canadian National Research Council (NRC) signed a memorandum of understanding that Canada would develop and construct the Shuttle Remote Manipulator System.
NRC awarded the contract to do so to SPAR Aerospace. Three systems were constructed within this design, development, test and evaluation contract: an engineering model to assist in the design and testing of the Canadarm, a qualification Model that was subjected to environmental testing to "qualify" the design for flight and a flight unit. Frank Mee is credited as the inventor of the Canadarm End Effector, its design was inspired by the opening and closing of a camera's iris. At his home, he fabricated a small model made out of cardboard and string; and brought it to work. His design won over the claw-like mechanisms that were being considered.
The main controls algorithms were developed by SPAR and by subcontractor Dynacon Inc. of Toronto. CAE Electronics Ltd. in Montreal provided the display and control panel and the hand controllers located in the Shuttle aft flight deck. Other electronic interfaces, servoamplifiers and power conditioners located on the Canadarm were designed and built by SPAR at its Montreal factory. The graphite composite boom that provides the structural connection between the shoulder and the elbow joint and the similar boom that connects the elbow to the wrist were produced by General Dynamics in the United States. Dilworth, Secord, Meagher and Associates, Ltd. in Toronto was contracted to produce the Engineering model end effector then SPAR evolved the design and produced the Qualification and Flight units. The Shuttle flight software that monitors and controls the Canadarm was developed in Houston, Texas, by the Federal Systems Division of IBM. Rockwell International's Space Transportation Systems Division designed, developed, tested and built the systems used to attach the Canadarm to the payload bay of the orbiter.
A acceptance ceremony for NASA was held at Spar's RMS Division in Toronto on the 11th of February 1981. Here Larkin Kerwin, then the head of NRC, gave the SRMS the informal name, Canadarm.
The first remote manipulator system was delivered to NASA in April 1981.
Design and Capabilities[edit | edit source]
The original Canadarm was capable of deploying or retrieving payloads weighing up to 332.5 kilograms in space. In the mid-1990s the arm control system was redesigned to increase the payload capability to 3293 kilograms in order to support space station assembly operations. Although the Canadarm can maneuver massive payloads in space, the arm motors are unable to lift the arm's own weight when on the ground. NASA therefore developed a model of the arm for use at its training facility within the Johnson Space Center located in Houston, Texas. The Canadarm can also retrieve, repair and deploy satellites; provide a mobile extension ladder for extravehicular activity crew members for work stations or foot restraints; and be used as an inspection aid to allow the flight crew members to view the orbiter's or payload's surfaces through a television camera on the Canadarm.
The basic Canadarm configuration consists of a manipulator arm; a Canadarm display and control panel, including rotational and translational hand controllers at the orbiter aft flight deck flight crew station; and a manipulator controller interface unit that interfaces with the orbiter computer. Most of the time, the arm operators see what they are doing by looking at the Advanced Space Vision System screen next to the controllers.
One crew member operates the Canadarm from the aft flight deck control station, and a second crew member usually assists with television camera operations. This allows the Canadarm operator to view Canadarm operations through the aft flight deck payload and overhead windows and through the closed-circuit television monitors at the aft flight deck station.
The Canadarm is outfitted with an explosive-based mechanism to allow the arm to be jettisoned. This safety system allows the Orbiter's payload bay doors to be closed in the event that the arm fails in an extended position and is not able to be retracted.
The Canadarm is 15 meters long, and 38 centimeters in diameter with six degrees of freedom. It weighs 410 kilograms by itself, and 450 kilograms as part of the total system. The Canadarm has six joints that correspond roughly to the joints of the human arm, with shoulder yaw and pitch joints; an elbow pitch joint; and wrist pitch, yaw, and roll joints. The end effector is the unit at the end of the wrist that grapples the payload's grapple fixture. The two lightweight boom segments are called the upper and lower arms. The upper boom connects the shoulder and elbow joints, and the lower boom connects the elbow and wrist joints. The Canadarm attaches to robots that are controlled from the flight deck.
In Popular Media[edit | edit source]
- In the movie Iron Sky, a Royal Canadian Air Force version of the Canadarm, named Canadarm 3, is an armed spacecraft that fights against the Nazis during the battle for the earth.
- On November 13, 2012, Google Canada displayed a doodle on its home search page to celebrate the 31st anniversary of the Canadarm's first use in space.
- The Canadarm was seen in Gravity being used to repair the Hubble Space Telescope.
|This page uses Creative Commons Licensed content from Wikipedia (view authors).|