New Canadian robotic arm boosts time for space experiments

The Canadian Space Agency on Thursday unveiled a dual-armed robotic module for the International Space Station that could vastly increase the time astronauts have to conduct experiments.

The Special Purpose Dexterous Manipulator, called Dextre, is to be used in construction and maintenance tasks that can currently be performed only by astronauts on spacewalks. The device, as well as the Canadarm2 that is permanently kept on the space station, can also be operated by people on Earth.

"We are the world leader in space robotics right now," Benit Marcotte, manager of the Canadian space station program at the Canadian Space Agency, told CBC News Online. "If the arm doesn't work, construction of the space station stops it's a critical role."

The unveiling was timed to coincide with a two-day visit from NASA astronauts Robert Behnken, Michael Foreman and Garrett Reisman, who saw Dextre for the first time at manufacturer MDA Corp.'s Brampton, Ont., facility on Thursday.

"The three astronauts who will be flying with Dextre in 2008 are here in Brampton to do their training," Marcotte said. "They're here to see the real hardware because they've been using a mock-up in the pool in Houston."

The pool the world's largest at about 61 metres long, 30.5metres wide, 12 metres deep and capable of holding about 23.5 million litres of water is the Neutral Buoyancy Lab at NASA's Johnson Space Center in Houston, Texas, which is used by astronauts to simulate low gravity conditions.

Assembled in orbit

If all goes according to plan, the robotic manipulator will be shipped to Cape Canaveral, Fla., in June, and launched to the space station in nine pieces on Feb. 14, 2008, where Behnken, Foreman and Reisman will assemble it.

The device is expected to reduce the amount of time astronauts spend on construction and routine maintenance, while increasing their safety and the time for conducting scientific experiments time now spent on extra-vehicular activities (EVAs), the technical term for spacewalks.

"For one spacewalk, you [are]looking at 100 hours of astronaut time," Marcotte said. "If you could save one EVA, a great portion of crew time can be saved."

Tasks to be conducted using Dextre which would attach to the Canadarm2 or the space station's Canadian-made external transport system would include installing and removing parts such as batteries and computers, connecting equipment to power sources and handling scientific packages.

Dextre is capable of sensing pressure, similar to the way in which a human can feel force when they are moving or assembling an object, and adjust its movements accordingly.

Not autonomous

However, Dextre is a long way off from having the kind of independence that robots in science fiction tales possess, Marcotte said.

"Is it capable of doing a task by itself? No, we're not there yet," Marcotte said, explaining that autonomous industrial robots such as those used in automotive manufacturing "are doing repetitive tasks in a controlled environment.

"We're doing mostly unique tasks that would be complex to program. Space is a very different environment and we're learning to walk before we run."

Dextre incorporates two seven-jointed arms and four video cameras to help astronauts inside the space station or flight controllers on Earth perform construction and maintenance tasks and see the work area.