Space robot's 'self-repair' means fewer spacewalks

Canada's "handyman" robot Dextre is repairing the International Space Station's Canadian robotic arm this week and in the process, it has taken over another task that once belonged to spacewalking astronauts.

Dextre is a space robot that can ride the Canadarm2 and wield a variety of tools with its two multi-jointed arms. It is currently in the middle of a week-long repair job to replace cameras on the Canadarm2 and its mobile base.

Using theCanadarm2andDextrereduces the overall number of spacewalks, definitely.- MathieuCaron, Canadian Space Agency

Together, Dextre, Canadarm2 and the base make up the space station's robotic Mobile Servicing System, making this the first ever robot self-repair in space, the Canadian Space Agency says.

"We've had to change cameras before, but we had to do it during spacewalks," said Mathieu Caron, mission control supervisor at the Canadian Space Agency, in an interview with CBCNews.ca.

This time, astronauts are barely involved in the work that began last Thursday and is scheduled to wrap up this coming Thursday. The robots are controlled remotely from the Canadian Space Agency headquarters in Longueuil, Que., and NASA's Mission Control Center in Houston, Texas.

Camera swap

Dextre is taking a camera on the Canadarm2 that has grown kind of hazy and is moving it to the mobile base to replace a completely broken camera. It will then install a new, spare camera on the Canadarm2.

The cameras are among 11 on the Mobile Servicing System that are used to control the robots and perform surveys outside the space station. The swap is taking place because the camera on the base is less critical than the one on the Canadarm2 itself, Caron said.

The astronauts' only involvement in the operation was to push the spare camera into an airlock so Dextre could grab it.

It's the first time a job like this has been done robotically, but it certainly won't be the last Caron says space agencies are increasingly relying on robots instead of humans to do work outside the space station whenever possible.

"Using the Canadarm2 and Dextre reduces the overall number of spacewalks, definitely," Caron said.

Spacewalks are inspiring demonstrations of technology and human exploration in an environment humans were never designed for the harsh, freezing cold, oxygen-free vacuum of space. But they are risky for astronauts compared to work inside the space station itself, where life-support systems keep temperatures, pressures and oxygen levels within tightly controlled limits.

"Spacewalks are very complex and use a lot of space station resources," Caron said. "They monopolize astronauts not only for the duration of the spacewalk, but in the weeks leading up to it for all their preparation."

That, he added, eats into valuable time that astronauts could otherwise spend running science experiments.

Robots also never need to return to the inside of the space station, making them more flexible.

"We can stop an operation and resume it later on."

Since Dextre was installed onthe space station in 2008, it has been used whenever possible for repair tasks and jobs such as unloading supplies sent to the station aboard unmanned space cargo ships.

So, are astronauts' spacewalking days over for good?

Not yet. Dextre still has its limitations it can largely only handle tools and hardware such as bolts and screws that are "robotically compatible." It has trouble removing coverings such as thermal blankets, for example.

But Caron said the space agency has been testing Dextre with equipment that isn't robotically compatible, such as hardware to refuel satellites.

• Canada's robot begins 1st satellite refuelling job

In the meantime, Dextre's agenda for the summer is already filling. It is scheduled to replace a circuit breaker in June and to repair equipment outside the space station to prepare for some astronaut spacewalks later in the summer, Caron said.

"The next year promises to be very busy from a Canadian robotics standpoint."

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