S89-27384 (5 Jan 1989) --- Astronauts James P. Bagian, left, and Robert C. Springer inspect a portion of the first stage of the Inertial Upper Stage (IUS-9) in a test cell of the KSC vertical processing facility. The two, along with three other NASA astronauts, will fly aboard Discovery and are responsible for the deployment of the tracking and data relay satellite (TDRS).