Terra (satellite)

Terra (EOS AM-1) is a multi-national NASA scientific research satellite in a Sun-synchronous orbit around the Earth. It is the flagship of the Earth Observing System (EOS). The name "Terra" comes from the Latin word for Earth.

Launch
The satellite was launched from Vandenberg Air Force Base on December 18, 1999, aboard an Atlas IIAS vehicle and began collecting data on February 24, 2000. It was placed into a near-polar, sun-synchronous orbit at an altitude of 705km, with a 10:30am descending node.

Mission
Terra carries a payload of five remote sensors designed to monitor the state of Earth's environment and ongoing changes in its climate system: Data from the satellite helps scientists better understand the spread of pollution around the globe. Studies have used instruments on Terra to examine trends in global carbon monoxide and aerosol pollution. The data collected by Terra will ultimately become a new, 15-year global data set.
 * ASTER (Advanced Spaceborne Thermal Emission and Reflection Radiometer)
 * CERES (Clouds and the Earth's Radiant Energy System)
 * MISR (Multi-angle Imaging SpectroRadiometer)
 * MODIS (Moderate-resolution Imaging Spectroradiometer)
 * MOPITT (Measurements of Pollution in the Troposphere)

Malicious Cyber Activities
In June and October 2008 the spacecraft was targeted by hackers who gained unauthorized access to its command and control systems but did not issue any commands.