Digi International Inc. has a new piece of business providing the eyes and ears of the world's first walking robot astronaut.

Robonaut, as NASA calls him, was sent to the International Space Station two years ago for certain maintenance tasks, such as polishing the railings and testing air circulation.

An upgrade coming soon will give the robot legs to move about the space station, and NASA hired Digi to provide the main circuitry for the change.

The Digi circuit board's processor chip will run Robonaut's five camera "eyes," and the board's Wi-Fi antenna will allow him to "hear" computer commands that tell him what to do next. Most of the time, his masters will be NASA's ground controllers rather than astronauts on the station, said Dan Huot, a spokesman for NASA's Johnson Space Center in Houston.

Robonaut is a world apart from Digi's usual business of connecting industrial equipment via Wi-Fi. The Minnetonka-based company, which was founded in 1985 to connect computers to printers, industrial controls and scanners via cables, switched to wireless networking in the early 2000s. It has more than 600 employees worldwide, including about 300 in the Twin Cities.

For Robonaut, NASA simply ordered about 100 copies of one of Digi's off-the-shelf circuit boards, which sell for less than $200.

"It was a small-dollar purchase, so the research team searched for the best vendor," Huot said. "Digi had the best value for the government at the time."

Selling a hundred circuit boards for less than $200 apiece wasn't a big sale for Digi, which last year earned $7.6 million on revenue of $190.6 million. But NASA is a terrific showcase account, said Joel Young, Digi's chief technology officer.

"It's a great proof point to show what our technology can do. And if it's used by NASA in Robonaut, think how well it will work for you in your medical device or industrial controller," Young said. "It demonstrates our commitment to quality and reliability. And you expect to get future opportunities, which I hope would be with both NASA and with commercial spinoffs of the technology."

One potential customer is General Motors, which is partnering with NASA on the Robonaut project in hopes of learning more about how to build industrial robots that are safe enough to work alongside humans.

Even with the Digi circuit board, Robonaut will have a limited run of the space station, Huot said. While the station is about the size of a football field, the inhabited portion is only about the size of a three-bedroom house. Within that space, Robonaut will do cleanup work on the U.S. part of the house. NASA shares control of the station with space agencies from four other countries.

"Monotonous, mundane tasks are perfect for a robot," Huot said.

But it won't all be dull work. Besides cleaning the space station, Robonaut will also check air circulation, which is critical because in zero-gravity the air doesn't move on its own, Huot said. An astronaut's exhaled breath would stay in front of his or her face, causing oxygen deficit problems. To prevent that, Robonaut will hold a device in front of an air vent to see if the air is being circulated around the space station at the proper speed.

And while NASA initially wanted Digi's circuitry to work when Robonaut was inside the space station, the agency said it might someday send Robonaut on a spacewalk.

That got Digi executives worrying a little.

"This is an off-the-shelf circuit board, not one customized for NASA," Young said. "Normally these circuit boards go into factory process controllers or into medical diagnostic devices."

Anxious to make sure the circuit board was up to the task of a spacewalk, Digi tested it for extremes of vibration, such as those it might encounter on a rocket launch, and for susceptibility to radiation, and rapid changes in humidity or temperature, all conditions found in space. The board passed all the tests.

"Our product comes with a five-year warranty, and we'll find out if it works that long in space," Young said. "It's a good opportunity for all of us to learn."