21.   Goldenthal said the robot arm, critical to all future construction on the station, is designed to have all of its parts replaced when needed.

22.   However, on Friday ground controllers said a computer software problem is preventing the robot arm from accepting electrical power from the new rail car platform.

23.   His team has helped design mufflers for the Canadian-built robot arm and damping systems for Russian airlock pumps.

24.   If the mission continues, the Columbia is to pursue Hubble for two days before snagging the telescope with its robot arm early Sunday.

25.   In December, shuttle astronauts caught up with the previously launched Zarya module and used the robot arm to link it with the Unity module.

26.   In response, researchers developed robot arms controlled by joysticks.

27.   It used a French submersible with robot arms and claws.

28.   Its robot arm was almost identical to the one on the ill-starred polar lander.

29.   Maneuvering the robot arms can be especially tricky because the pilot has only a two-dimensional view but is operating in a three-dimensional environment.

30.   Normally, the spacewalking astronauts are double-tethered to the structure of the station or the tip of the robot arm as they work.