The original finding aid described this as: Description: View of the deployed tracking and data relay satellite (TDRS) and its inertial upper stage (IUS) photographed from the aft flight deck window of the shuttle Challenger. The second multicolored cluster is a window reflection. View captures the relative separation between the TDRS and the Challenger. Many views are very dark. Subject Terms: INERTIAL UPPER STAGE PAYLOAD DEPLOYMENT & RETRIEVAL SYSTEM TDR SATELLITES STS-6 CHALLENGER (ORBITER) ONBOARD ACTIVITIES Categories: Payloads Interior_Exterior: Exterior Ground_Orbit: On-orbit Original: Film - 70MM CT Preservation File Format: TIFF feat: IUS/TDRS SEPARATION.