Dextre, also known as the Special Purpose Dexterous Manipulator (SPDM), is a two-armed robot, or telemanipulator, which is part of the Mobile Servicing System on the International Space Station (ISS), and does repairs that would otherwise require astronauts to do spacewalks. It was launched on March 11th, 2008 on the mission STS-123. Dextre is a part of Canada's contributions to the ISS and was named to represent its dexterous nature. Dextre is the newest of three Canadian robotic arms used on the ISS, preceded by the Space Shuttle's Canadarm and the large Canadarm2. Dextre was designed and manufactured by MDA. In the early morning of February 4, 2011, Dextre completed its first official assignment which consisted of unpacking two pieces for Kounotori 2 while the on-board crew was sleeping. Purpose Dextre is designed to handle and complete orbital replacement units: Many spares are stored on the ISS and Dextre is able to carry them to and from worksites and install replacements when failures occur. Before Dextre arrived astronauts were required to perform space walks to carry out this long work. Structure Dextre resembles a gigantic torso fitted with two extremely agile, arms. Total mass is about . The 3.5-metre-long body pivots at the "waist". The body has a Power Data grapple fixture at the 'head' end that can be grasped by the larger Space Station Arm, Canadarm2 so that Dextre can be positioned at the various Orbital Replacement Unit (ORU) worksites around the Space Station. The other end of the body has a Latching End Effector virtually identical to that of Canadarm2, so that Dextre can also be attached to Space Station grapple fixtures or the Mobile Base System. Dextre can also be operated whilst it is attached to the end of Canadarm2. Each arm is somewhat like a shortened Canadarm2 (in that it has 7 joints) but is fixed to Dextre at one end. At the end of Dextre's arms are ORU/Tool Changeout Mechanisms (OTCM). The OTCM has built-in grasping jaws, a retractable socket drive, a monochrome TV camera, lights, and an umbilical connector that can provide power, data, and video to/from a payload. Dextre moves one arm at a time, while one arm may hold onto the station (using specially provided standard H or Micro interfaces) for stability and ease of control the other is available to perform tasks. Tools The lower body of Dextre has a pair