"SILTS camera infrared image of the flight surfaces of Columbia during STS-28 reentry."
"The Shuttle Infrared Lee-side Temperature Sensing (SILTS) camera package made its second flight aboard Columbia on this mission. The cylindrical pod and surrounding black tiles on the orbiter's vertical stabilizer housed an imaging system, designed to map thermodynamic conditions during reentry, on the surfaces visible from the top of the tail fin. Ironically, the camera faced the port wing of Columbia, which was breached by superheated plasma on its disastrous final flight, destroying the wing and, later, the orbiter. The SILTS system was used for only six missions before being deactivated, but the pod remained for the duration of Columbia's career. Columbia's thermal protection system was also upgraded to a similar configuration as Discovery and Atlantis in between the loss of Challenger and STS-28, with many of the white LRSI tiles replaced with felt insulation blankets in order to reduce weight and turnaround time. One other minor modification that debuted on STS-28 was the move of Columbia's name from its payload bay doors to the fuselage, allowing the orbiter to be easily recognized while in orbit."
Information from Wikipedia: link
Date: August 13, 1989
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