Launch was originally scheduled for March 9, 1991, but during processing work at Pad LC-39A, significant cracks were found on all four lug hinges on the two external tank umbilical door drive mechanisms.

The mission was again postponed when, during prelaunch external tank loading, a transducer on high-pressure oxidizer turbopump for main engine number three showed readings out of specification.

Unclassified payload included Air Force Program-675 (AFP-675); Infrared Background Signature Survey (IBSS) with Critical ionization velocity (CIV), Chemical Release Observation (CRO) and Shuttle pallet satellite-II (SPAS-II) experiments; and Space Test Payload-1 (STP-1).

There had previously been seven Shuttle missions dedicated to the DoD, but those were considered classified and information about the operation or success of the payloads or experiments was not released.

Carried in the orbiter's cargo bay were: Air Force Program-675 (AFP-675); Infrared Background Signature Survey (IBSS); Space Test Program-01 (STP-01); and the MPEC.

The Remote Manipulator System (Canadarm) in the payload bay was used to deploy the Shuttle Pallet Satellite-II (SPAS-II), on which the IBSS was mounted.

The high orbital inclination of the mission, 57.01° with respect to the equator, allowed the crew to fly over most of Earth's large land masses and observe and record environmental resources and problem areas.