On spacewalks, one astronaut's job is sometimes to just hand tools to another astronaut. It's a simple role but risky, considering that a tiny tear in his spacesuit could rob him of oxygen. This month, NASA will introduce a more durable—and expendable— astronaut when it sends the first android into space: Robonaut 2.
Robonaut, built by NASA and GM, is a head, torso and arms that will be anchored inside the International Space Station. After testing and upgrades, it will graduate to spending time attached to the station's exterior, where it will be most useful. Astronauts' bulky gloves make handling tools difficult; Robonaut could hang on to runaway tools and aid with more-complicated tasks. And whereas an astronaut takes at least six hours to prep for a spacewalk, Robonaut could boot up for emergency repairs in minutes.
Recognizing the need for more spacebots, the German Aerospace Center, DLR, has constructed Justin, a robotic torso with similar talents. "There is a friendly competition between us," says Gerd Hirzinger, DLR's head of robotics. Germany will probably need to work with other countries to put Justin on a Mars rover or the ISS, but one day the 'bot could rove on its own spacecraft, repairing satellites. Here's how the two robots match up.
Round One: Strength
Justin: Even in microgravity, it takes force to move mass. Each of Justin's carbon-fiber arms can lift 31 pounds
Robonaut: Robonaut can lift just 20 pounds per arm, but that's enough to shift the ISS's giant solar batteries
Round Two: Vision
Justin: Stereo vision from two high-definition cameras and object-recognition software
Robonaut: Stereo vision plus an infrared camera for sonar-like depth perception to easily track moving objects
Round Three: Hands
Justin: Justin's four chunky fingers could have difficulty with normal tools, but its hands could swap out Mr. Potatohead-style for other gadgets
Robonaut: Robonaut's five human-size fingers let this robot use the same tools as astronauts. No special implements required
Round Four: Controls
Justin: From Earth, a person would control Justin by wearing an exoskeleton with force feedback
Robonaut: In the future, an astronaut will determine Robonaut's movements using a virtual reality helmet and a light-based motion-tracking system similar to an Xbox Kinect
Round Five: Power Supply
Justin: Mounted on its own spacecraft, Justin could get power from solar panels, with batteries for backup
Robonaut: Robonaut would wear exchageable battery backpacks for spacewalks, with conversion equipment to run off the ISS electrical system
Round Six: Programmed Dance Moves
Justin: John Travolta's twist from Pulp Fiction
Robonaut: Tai chi-like demonstrations of flowing grace and strength
And the winner is... Robonaut 2
Infrared vision, five-fingered hands and a tested power scheme make it the superior spacebot.