Astronauts of the future, meet your competition: When the space shuttle Discovery launches later today, Robonaut 2 (R2)—seen above on the left—will become the first humanoid robot in space.
R2 is bound for the International Space Station, and scientists will spend a year simply studying how well the robot moves in zero G. Once mission managers are satisfied, the android will be assigned one of its first tasks: house cleaning.
To keep the crew healthy, astronauts on the ISS have to use disinfecting wipes on all handrails every week. "Jobs like that are really crummy for humans," said Robert Ambrose, the Robonaut project leader at NASA's Johnson Space Center in Texas. Fortunately for the ISS crew, R2 wasn't programmed for snarky backtalk.
These days, plenty of robots have landed on other planets and been put to work. Still, building a machine that can operate in microgravity around humans but without human control was a unique challenge. The mature, responsible R2 owes its shot at glory in space to a host of robotic "ancestors," earlier androids that never left Earth as well as less human-like machines that are already hard at work on the ISS.
Photograph by Robert Markowitz and Bill Stafford, NASA
R2's immediate predecessor, Robonaut 1 could be attached to a four-wheeled rover to become Centaur, allowing the android to explore other worlds. Seen above during 2006 field tests, the model never got much closer to space than Meteor Crater in Arizona.
Unlike the partly autonomous Robonaut 2, R1 used only "telepresence," meaning that its actions were remotely controlled by a human operator. But both robots share some of the same actuators and sensors, so that the design team didn't have to "reengineer everything from scratch," Ambrose said. (See pictures: "'Ghost' Robot Lets User Cuddle, Chat Remotely.")
Using technology designed for R1, NASA, and General Motors—which is interested in developing androids that can safely operate side by side with humans on a factory floor—built the faster, smarter, and more sensitive R2.
Photograph courtesy NASA
Nonhumanoid robots, such as the Special Purpose Dextrous Manipulator, or Dextre, are already blazing trails in space. Outfitted with a camera, lights, and a tool belt, Dextre is an artificial "handyman" that's remotely controlled by astronauts inside the International Space Station.
Installed on the ISS in 2008, Dextre spent nearly two years undergoing tests. Not that the robot's been slacking off: As part of the testing, Dextre swapped out circuit breakers to save astronauts the danger of a spacewalk and moved heavy cargo around to make room for more scientific instruments. (Related: "Astronauts' Fingernails Falling Off Due to Glove Design.")
The robot's first official assignment came earlier this month, when it unloaded cargo from Japan's uncrewed HTV-2 spacecraft.
Illustration courtesy MacDonald, Dettwiler and Associates
Ranger, seen in a neutral-buoyancy tank in College Park, Maryland, never reached space—but not because it wasn't ready.
Built on a budget price tag of $20 million in the 1990s, the nonhumanoid robot was designed to service satellites and possibly even the Hubble Space Telescope. But the robot wasn't set to fly on a space shuttle until just before the 2003 Columbia tragedy, which led to NASA canceling several planned science missions. (See "Columbia Tragedy A Setback For Science.")
Like Robonaut, Ranger could manipulate objects in both hands and pass an object from one hand to the other. "It's fairly unusual [for a robot] to be able to do two-hand motion with a component in both hands," said Ranger project leader Dave Akin of the University of Maryland.
Photograph courtesy Dave Akin, Space Systems Laboratory, University of Maryland
In perfect human-robot synergy, astronaut Stephen Robinson stands anchored to the end of the ISS's Canadarm2 during a spacewalk.
Installed on the ISS in 2001, the remote controlled Canadarm2 has seven joints and the ability to move anywhere on the station by crawling like an inchworm or tumbling end-over-end like a Slinky across the hull.
Compared to R2, Canadarm2 is an old hand—the robot has already assisted with 97 spacewalks and unloaded 43 sets of cargo. It may even have a future career in baseball: In 2009, Canadarm2 successfully snagged a free-flying cargo vehicle intentionally aimed at the ISS.
Photograph courtesy NASA
Flight Telerobotic Servicer
Not only did the Flight Telerobotic Servicer (FTS) never reach space, it barely got off the ground.
Seen above in an illustration, the FTS was designed in the 1980s as a catch-all robot that would help assemble and maintain the ISS, which was then being called Freedom. According to initial specifications, the robot was supposed to perform spacewalks and other hazardous tasks, as well as the routine chores that will become Robonaut 2's bread and butter.
In 1987 the FTS was considered an integral part of the space station program. Just four years later the project was killed due to "significant cost overruns," NASA administrator Daniel Goldin told a group of aerospace executives in 1992. A government report on the state of space robotics at the time drily concluded: "Robotics technologies were oversold in the 1980s."