When the space shuttle Endeavour launches early Tuesday morning, it will hold the makings of a 3,400 pound, 12-foot-tall robot with a 30-foot wingspan.
The robot, named Dextre by its makers at the Canadian Space Agency in Saint-Hubert, Quebec, is slated to become the newest part of the crew at the International Space Station. The $200 million robot is expected to take on most of the maintenance jobs required outside of the space station, thus cutting back on the number of dangerous space walks the astronauts must make.
"Dextre is the most sophisticated space robot to ever to be launched," said Pierre Jean, acting program manager of the Canadian Space Station program. "The fact is that up to this point, any time things failed in orbit, crew members had to go out and deal with it. Now they can use a robot to fix hardware with 2-millimeter precision."
Canadian engineers have been working on Dextre -- pronounced Dexter -- for the past 10 years. With a sense of touch, two 11-foot arms and a wingspan of 30 feet, Dextre can work with objects as large as a phone booth or as small as a phone book, according to Jean.
"Dextre was designed to make sure the International Space Station keeps working," added Jean. "There are 138 boxes on the outside of the space station. They're primarily the electronics behind the backbone of the space station, like remote power-controller modules, DC-to-DC converter units and a nitrogen tank assembly. These are the boxes that Dextre can work on. When some of these big electronic boxes fail and systems are affected, the station could be reduced in functionality. Dextre could go off and fix it, and keep the International Space Station running at full capacity."
The Endeavour's crew is scheduled to start a 16-day mission tomorrow that will include installing the first piece of Japan's three-part Kibo laboratory, running experiments and assembling the giant robot.
Jean said Dextre is going into space in nine pieces on a pallet in the shuttle's cargo bay. If the robot was placed fully assembled in the shuttle prior to takeoff, it wouldn't be able to withstand the shaking and rattling. More important, though, Dextre can't be assembled on Earth because it needs the weightlessness of space. On Earth, it wouldn't be able to bear up under its own bulk, Jean said.
"It's never been built [into one piece] on Earth," said Jean in an interview with Computerworld. "It's very strong and can maneuver large payloads in space, but it can't withstand its own weight. The first time Dextre will be assembled and operated as an entire system will be after launch."
Jean noted that the robot should be put together and operational in two weeks. As it's scheduled now, on Flight Day 3, Canadarm 2, which is a large robotic arm that has been on the space station for the past seven years, will reach into the shuttle's cargo bay and bring the pallet with Dextre's parts on it over to the space station.
On Flight Day 4, two astronauts will make a space walk, attaching Dextre's grippers, or hands, to its arms.
On Flight Day 6, two space walkers will attach the arms to the robot's body.
On Flight Day 8, astronauts will attach the machine's tool holder assembly, along with a maneuverable high-resolution color camera with lights.
At that point, Dextre will be ready for testing. The first tests, Jean said, will focus on the brakes in the robot's joints. Once the tests are successfully completed, astronauts will use a power data grapple fixture to attach Dextre's feet to the U.S. lab. It will receive all of its power and data through that attachment.
Dextre, which can move its wrists, elbows and shoulders while also twisting at the waist, can be controlled from inside the space station or from Earth.
Jean said he's not nervous that the robot will be assembled and fully tested for the first time in outer space.
"Everything has been electrically connected. All the signals and all the commands have been tested. It's all been done," he added. "All the mechanical fits, like will the arm fit on the body, have been tested. We don't take any chances on things like that not working. It's never been all assembled and sitting in one place, but everything we can do to test it has been done."
Jean laughed at published reports that a member of the shuttle's crew called Dextre "a little monstrous."
"Dextre is a member of the family. It may look imposing because essentially he was conceived to mimic what the space walker will do in space. He's just taller with longer arms," said Jean. "It's like a dream. You almost want to pinch yourself. It's kind of bittersweet. It's like sending your kids off to college. You want them to go off and make good for themselves, but there's a tinge of sadness that they're gone."
As of Monday afternoon, the shuttle was still scheduled to launch at 2:28 a.m. on Tuesday.