March 7, 2008
Rookie Robot Joins Crew of Space Shuttle
Space shuttle Endeavour is scheduled to blast off Tuesday carrying seven astronauts and an eighth passenger that is in some ways superior: a robot that will take the astronauts' place for many jobs in outer space.
Dextre, as the robot is known, has two arms, each with seven joints that allow the limb to twist and bend more than a human arm. Each of its two hands has pincers to grip objects and built-in socket wrenches to drive bolts.
"As spacewalkers, we don't want to put ourselves out of a job," Endeavour astronaut Mike Foreman says. "But I think (the robot) will be a boon."
Endeavour's crew will assemble Dextre and place it on the International Space Station, where it will start work in 2009. Eventually it will shoulder tasks that would otherwise be done by astronauts during risky spacewalks. Ten years in the making, the robot has a working life of 15 years.
Endeavour is scheduled to lift off at 2:28 a.m. ET. During the 16-day mission, the longest flight ever to the station, the crew will perform five spacewalks, the most during any station mission. The astronauts' goals, besides adding Dextre:
*Delivering the station's first Japanese section, an equipment room for a Japanese laboratory to be added to the station in May. A February shuttle mission dropped off the station's first European segment, a laboratory.
*Testing the last major safety improvement made after the 2003 breakup of shuttle Columbia, which killed the crew. Astronauts will experiment with a goo for patching holes in the shuttle's heat shield.
*Inspecting a broken wheel that points half the station's solar panels at the sun. The malfunction, first detected last fall, has cut the amount of electricity supplied to the station.
The mission will be an exhausting long haul, Endeavour commander Dom Gorie says, but piecing together the $210 million Dextre will be particularly tough.
Dextre is riding to orbit in nine pieces. Over the course of three spacewalks, astronauts will attach the hands to the robot's 11-foot-long arms. Then they'll lift the arms, which on Earth would weigh 775 pounds each, to Dextre's shoulders and bolt them into place.
"Some assembly required," Foreman jokes. "It reminds me of (being) a dad on Christmas Eve and opening up presents to put together ... and wondering what I got myself into."
Dextre will be able to replace nearly 140 parts of the station, such as batteries and circuit boxes. It will do so thanks to a sense of touch, which will allow it to "feel" when it needs to apply more force to slide a component into place. It's expected to aid astronauts not only with spacewalks but making repairs.
Dextre can be operated by either Mission Control or by the crew living on the station. NASA has no estimate of how many hours of astronaut time the robot will save, but the Canadian Space Agency, which built Dextre, says the robot will make repairs to the station as often as six times a year.
"He's almost like Spot the Pet Robot," says Endeavour astronaut Rick Linnehan, who will help put Dextre together. "He's going to go out there and get lots of important work done for you so you don't have to worry about it."