Delivery and installation of the arm is one of NASA's more complicated robotics missions to date. Here is how it is supposed to go:
The shuttle's arm, which NASA now refers to as the "little arm," will take the new robotic arm in its packing crate from the payload bay and hook it to the space station. Once the "big arm" is unfolded by space-walking astronauts, it will attach to the space station and then hand its 3,000-pound packing crate to the little arm.
The little arm will put the crate in the shuttle for return to Earth. Canadian astronaut Chris Hadfield calls it a symbolic "baton pass" between the two arms.
Canadarm2 is the first segment of a three-part Mobile Servicing System that eventually will allow station crews to move their robot helper anywhere on the growing station and perform intricate work now only possible with space-walking astronauts.
Next year, the arm will be attached to a mobile base platform that will move on rails along the girder-like truss that will span the station. And in 2004, the arm will get a hand. The Canada Hand, or dexterous manipulator, is a smaller, two-armed robot with sensors that give it a sense of "feel." This will allow it to do delicate, intricate tasks now handled by space walkers.
The robotic arm is the centerpiece of Canada's contribution to the U.S.-led station project. Canadian officials estimate they have spent $1.4 billion Canadian dollars, or U.S. $1 billion, designing, building, and testing the arm and its components.
Developing space robotics, first for the shuttle and now the station, is a source of national pride in Canada and has spurred a growing robotics industry in that country.
Endeavour is also carrying an Italian cargo module crammed with equipment for the station and supplies for the outpost's three-person crew. After docking with the station about 240 miles above Earth and delivering its cargo, the shuttle is scheduled to return to the Kennedy Space Center on April 30.