The orbiter payload bay contained only the Chandra spacecraft, the IUS, and the IUS tilt tableTthe following payloads were carried in the shuttle’s cabin: STL-B (Space Tissue Loss), CCM (Cell culture module), SAREX-II (Shuttle Amateur Radio Experiment), EarthKam, PGIM (Plant Growth Investigations in Microgravity), CGBA (Commercial Generic Bioprocessing Apparatus), MEMS (Micro-electric Mechanical System), and BRIC (Biological Research in Canisters) and SWUIS (the Southwest Ultraviolet Imaging System, an 0.18-m UV telescope to be used for airglow and planetary observations); GOSAMR (the Gelation of Sols: Applied Microgravity Research experiment) and LFSAH, the Lightweight Flexible Solar Array Hinge. MSX and SIMPLEX experiments were also to be carried out.
Chandra/IUS-27 was deployed from Columbia at 11:47 GMT July 23. Flight duration was limited; this was the heaviest shuttle (122,534 kg) and heaviest payload (19,736 kg) to that date. Columbia landed at 03:20 GMT on July 28 on runway 33 at Kennedy Space Center. Post-flight inspection found the presence of holes in the cooling lines on the nozzle of SSME 2019 (engine 3) which caused a hydrogen leak. A loose repair pin in the engine broke free and caused the failure. The cause of the short was found to be chaffed wiring inside the shuttle. The entire fleet was grounded for inspection and replacement of wiring as necessary.
GOES 12 was a 980 kg, 973 W spacecraft that carried an IR imager, a "sounder", and an X-ray imager. The IR imager was a Cassegrain telescope covering five wavelength channels, 0.55-0.75, 3.80-4.00, 6.50-7.00, 10.20-11.20, and 11.50-12.50 microns. It provided images covering 3,000 km x 3,000 km every 41 seconds, by scanning the area in 16 square kilometer sections. The "sounder" provided vertical distribution of temperature, moisture and ozone, by passive monitoring in 18 depth-dependent wavelengths. (Long wave IR: 14.71, 14.37, 14.06, 13.64, 13.37, 12.66, and 12.02 microns. Medium wave IR: 11.03, 9.71, 7.43, 7.02, and 6.51 microns. Short wave IR: 4.57, 4.52, 4.45, 4.13, 3.98, and 3.74 microns. There was also another band at visible wavelength 0.7 microns, to provide pictures of cloud tops.) The sounder covered an area of 3,000 km x 3,000 km in about 42 minutes. Another instrument package named SEM (Space Environment Monitor) monitored the energetic electrons and protons in the magnetosphere and the X-rays from the Sun. The above three had been carried on the earlier GOES missions, but GOES 12 carried also an X-ray imager providing an X-ray (about 0.1-1.0 nm wavelength) picture of the solar disk. For some months, the spacecraft was to be on standby, to be activated and moved to a desired longitude. As of 5 September 2001 located at 89.93 deg W drifting at 0.001 deg W per day. As of 2007 Mar 11 located at 74.73W drifting at 0.014E degrees per day.