1993年1月13日 · The STS 54 mission was the third flight of the orbiter Endeavour and was used to launch the sixth satellite in the Tracking and Data Relay Satellite (TDRS) series, TDRS-F. In addition, STS 54 carried a shuttle bay instrument called the Diffuse X-ray Spectrometer, or DXS, to make observations of the diffuse x-ray background in the Milky Way galaxy.