As the space station gets its finishing touches (
The ERA is like a disembodied arm with hands—actually cylindrical "end effectors"— on either end. While one hand holds onto an attach point on the station's exterior, the other is free to move cargo around. This video shows the ERA in action. The arm can also "walk" around the outside of the station from one attach point to another, with each step taking 30 minutes to an hour.
Unlike other station arms, the ERA can be operated either from inside the Russian lab module or from outside, by a spacewalking cosmonaut. For the first time, spacewalkers will be able to operate their own robot assistants, without having to ask one of their colleagues inside. At right is the control device they'll use.