STS-54

The primary payload was the fifth Tracking and Data Relay Satellite (TDRS-F) which was deployed on day one of the mission. It was later successfully transferred to its proper orbit by the Inertial Upper Stage booster. Also carried into orbit in the payload bay was a Hitchhiker experiment called the Diffuse X-ray Spectrometer (DXS). This instrument collected data on X-ray radiation from diffuse sources in deep space.