Terra launched in a sun-synchronous orbit on December 18, 1999. Terra is the flagship of the NASA Earth Observing System (EOS), a series of spacecraft that represent a landmark step in NASA's role to observe Earth from the unique vantage point of space. Terra focuses on measurements identified by a consensus of U.S. and international scientists enabling research into the ways that Earth's lands, oceans, air, ice, and life function as a total environmental system.
- ASTER – Advanced Spaceborne Thermal Emission and Reflection Radiometer
- CERES – Clouds and the Earth’s Radiant Energy System
- MISR – Multi-angle Imaging SpectroRadiometer
- MOPITT – Measurements of Pollution in The Troposphere
- MODIS – Moderate Resolution Imaging Spectroradiometer. MODIS delivers sea surface temperature (SST), atmospheric temperature, cloud temperature, cloud altitude, water vapor, ocean color and aerosol data. The MODIS instruments on board the Terra and Aqua EOS satellites acquire data with global coverage every 1-2 days.