TIRS completed its first round of thermal vacuum testing on Tuesday, October 4, marking the first time engineers evaluated the fully-assembled instrument at its normal operating temperature. When operational, TIRS is only 43 Kelvin (-382 °F). Such a cold temperature is necessary so the instrument itself does not overwhelm the heat radiated by Earth.
The Landsat Program is a series of Earth observing satellite missions jointly managed by NASA and the U.S. Geological Survey. Landsat satellites have been consistently gathering data about our planet since 1972. They continue to improve and expand this unparalleled record of Earth's changing landscapes for the benefit of all.