SAGE III on Меtеоr-3М (SAGE III/Meteor-3M) was a third generation, satellite-borne instrument and a crucial element in NASAs Earth Observing System (EOS). The instrument was launched on the Russian Метеор-3М spacecraft in December 2001 to measure aerosols, ozone, water vapor, and important trace gases in the upper troposphere and stratosphere, to study human-derived changes in climate and ozone. The mission ended when a power supply problem cut off satellite communication.