Making up one piece of the most advanced and accurate atmospheric chemistry laboratory ever deployed in space, the Microwave Limb Sounder, or MLS, instrument flies aboard NASA's Aura Earth satellite with three other instruments.

The Microwave Limb Sounder is designed to study the natural thermal radiation emitted from Earth's limb (the edge of Earth's atmosphere) to gather measurements on atmospheric gases, temperature and pressure. These data can be used to better understand the causes of ozone changes and pollution in the upper troposphere.