Stratospheric Aerosol and Gas Experiments (SAGE III)

SAGE III is a fourth generation, satellite-borne instrument and a
crucial element in NASA's Earth Observing System (EOS). Its mission is
to enhance our understanding of natural and human-derived atmospheric
processes by providing accurate long-term measurements of the vertical
structure of aerosols, ozone, water vapor, and other important trace
gases in the upper troposphere and stratosphere.