Robots In Space

In the bottom  we see the Canadarm robot arm, a version of which has flown on every Space Shuttle flight for the last twenty years. The arm has a shoulder with 2 DOF, an elbow with 1 DOF and a 3 DOF wrist. The arm is routinely used as a mobile work platform for the astronauts, for "tossing" satellites into space and for retrieving faulty ones. Non-routine uses have included: knocking a block of ice from a clogged waste-water vent, pushing a faulty antenna into place, and activating a satellite that failed to 
 go into proper orbit. Several of these arms have been in service for twenty years. A true robot success.