Dexterous Robot Designed for Spacework

H O U S T O N, July 24, 2000 -- The scientists behind NASA’s newest robot have outfitted their creation with an ancient tool that’sstill a giant leap forward: hands.

And who can blame them? Look what hands did for human evolution. Robonaut, the space agency’s latest-generation robot, has a handthat no other machine of its kind has ever had. Where other robotscould simply pick objects up with grippers, Robonaut has fourfingers, a thumb and a handshake to make a politician envious.

Big Leap For Robot Kind

Robonaut’s hands are nimble enough to pick up a small metalwasher with tweezers or squeeze the trigger on a variable-speeddrill. One noted roboticist calls Robonaut’s hand “a masterworkdevelopment.”

“It is a big leap for robot kind,” says Red Whittaker, thefounder of the Field Robotics Center at Carnegie MellonUniversity’s Robotics Institute. Designed as a remote-controlledspace helper, Robonaut was built to work with the same tools aspacewalking astronaut would use.

“The idea was essentially to create a surrogate for theastronaut,” says NASA engineer Chris Lovchik, who designedRobonaut’s hands. “We’re putting the astronaut’s training into therobot, and putting the robot out to perform the drudgery in thehazardous conditions of space.”

Hands alone aren’t enough for that kind of work.

So Robonaut’s designers at NASA’s Dexterous Robotics Laboratoryhave given their creation an arm, a torso, a head and video-cameraeyes. When the full prototype is completed later this year,Robonaut will have a second arm and hand and a single leg toprovide hands-free support.

That’s all downhill work after the challenge of building thehand and arm, says project director Robert Ambrose.

“We’ve gone after the hardest part first,” Ambrose says.

Though its grip is only about half that of a human and the armcan lift only 21 pounds, that’s more than enough strength to workin the weightlessness of space.

Control By Touch

Robonaut’s controls are straight out of popular science fiction.The controller wears a pair of stereoscopic goggles which displaywhatever Robonaut’s camera eyes see, and wears a sensor-filledglove to control the hand and arm.

Just moving the glove tells Robonaut how far to extend its armsor twist its wrist. Once the technology is refined, the glove willprovide a sense of touch to the operator, Ambrose says.

So far, operators have only their eyes to guide a hand that hasabout half the dexterity of a human hand. Engineers measuredexterity by degrees of freedom. While Robonaut has 12 degrees inits hand; humans have 22, Lovchik says.

The one-time watchmaker dissected several human hands at areamedical schools to learned how to translate the mechanics of fleshand blood into a metal-and-plastic machine.

“The reason the human-like form is so important is because weare the ones who have contrived the world,” says Whittaker, whodeveloped a robot to facilitate cleanup of the failed Three MileIsland nuclear plant and another one to search for meteoritefragments in Antarctica. “Robonaut is well-suited since we havespacecraft for people, tools for people and all of the devices wetake for granted in everyday life, like doorknobs.”

The three-year, $3 million project was funded only to see if thelab could produce a robot that can work with astronaut tools withthe dexterity of a suited astronaut, Ambrose says.

Though it was built with parts already rated to withstand therigors of space travel, Robonaut won’t see orbit for at least fiveyears, Ambrose says.

Handyman and Explorer

In space, Robonaut could prepare exterior work sites forastronauts, saving valuable spacewalk time for more importanttasks. But if early success is any indicator, Robonaut’s futureapplications are fairly limitless, Ambrose says.

“Wouldn’t it be great if every spacecraft had a robot thatcould go out and perform repair work while it’s in flight?”Ambrose asks.

Ambrose envisions such an application for future planetaryexploration missions. The same Robonaut could be mounted on a landrover to explore an unknown planet’s surface in a configurationAmbrose likens to the Centaur, the half-man, half-horse of Greekmythology.

On Earth, Robonaut could be used in the hazardous conditionsfound in nuclear plants or petroleum refineries, and NASA saysprosthetic makers have expressed interest in the hand.

But Ambrose’s goal is less specific. He simply wants Robonaut toperform human tasks with high fidelity. Then, the technology’sreach would be limited only by its human operators and theirimaginations.

“At the point when you stop thinking about it as a Robonaut andthink of it as an extension of a person, we’ve succeeded,” Ambrosesays.