Space Station Crew Assembles Dextre Robot During Second Spacewalk

The two spacewalkers assembled the stick-figure-shaped Dextre, also known as the Special Purpose Dextrous Manipulator (SPDM), a task that included attaching its two arms.

Designed for station maintenance and service, Dextre is capable of sensing forces and movement of objects it is manipulating. It can automatically compensate for those forces and movements to ensure an object is moved smoothly.

More than just a hand, Dextre is a robot with two smaller arms. It is capable of handling the delicate assembly tasks currently performed by astronauts during spacewalks.

The two arms will allow Dextre to transport objects, use tools, and install and remove equipment on the space station. Dextre also is equipped with lights, video equipment, a tool platform and four tool holders. Sensors will allow the robot to "feel" the objects it is dealing with and automatically react to movements or changes. Four mounted cameras will allow the crew to observe what is going on.

Astronauts will operate Dextre remotely from inside the space station. The robot is designed to function as a part of a spacewalk team, working with astronauts, or to work independently on tasks that previously would have required a spacewalk, allowing the crew to remain inside the station.

Dextre's design somewhat resembles a person. The robot has an upper body that can turn at the waist and shoulders that support arms on either side. Each arm is 11.5 feet in length and has a total of seven joints, allowing a wide range of possible movements. The arms are able to handle masses of up to 1,327 pounds. Each arm has a "hand" with parallel retractable jaws that can grip objects, a retractable motorized socket wrench, lights and a camera.