For three years, Robonaut has had to manage from the waist up at the International Space Station. This new pair of legs means the experimental robot won't be stuck on a pedestal and can go mobile.
The robot's legs are packed aboard a SpaceX supply ship that launched Friday, more than a month late. The cargo arrives on Easter Sunday morning.
It's the next big step in Nasa's quest to develop robotic helpers for astronauts. With legs, the 8-foot Robonaut will be able to climb throughout the space station, performing mundane cleaning chores and fetching things for the human crew.
Each leg has seven joints. Instead of feet, there are grippers, each with a light, camera and sensor.