The Microwave Limb Sounder (MLS) was one of ten scientific instruments on the Upper Atmospheric Research Satellite (UARS), a NASA project operative from 1991-2005. The satellite's suite of instruments researched the “greenhouse effect” (the impact of increased CO2 concentrations in the atmosphere) and the ozone hole over Antarctica. A central element of NASA's "Mission to Planet Earth", UARS provided critical data on the chemical and physical interactions between Earth's upper and lower strata of atmosphere.
The MLS's Ghz Receiver helped analyze the behavior and effects of several molecules in the upper atmosphere, particularly chlorine monoxide, a molecule that breaks down and depletes atmospheric ozone.
NASA transferred this object to the museum in 2016.
This object is on display in One World Connected at the National Air and Space Museum in Washington, DC.