US space shuttle readies launch of German craft

Crew members of the orbiting space shuttle Challenger ran through a trouble-shooting checklist of a West German test satellite they will launch and retrieve Wednesday. The only problem encountered was a minor one - a data handling difficulty with one of the experiments on the satellite.

Otherwise, the American spaceship performed flawlessly Monday on the third day of its voyage. The German satellite was built as a platform for rent to anyone who wants to fly instruments in space. It is called SPAS, for ''shuttle pallet satellite.'' The satellite carries 11 scientific and engineering experiments.