Approximately the size of a small school bus, the Terra satellite carries five instruments that take coincident measurements of the Earth system:
- Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER)
- Clouds and Earth’s Radiant Energy System (CERES)
- Multi-angle Imaging Spectroradiometer (MISR)
- Measurements of Pollution in the Troposphere (MOPITT)
- Moderate Resolution Imaging Spectroradiometer (MODIS)
Terra is in a circular sun-synchronous polar orbit that takes it from north to south (on the daylight side of the Earth) every 99 minutes.
Spacecraft Quick Facts:
- Launch Date: December 18,1999
- Size: the spacecraft bus is 6.8 m long and 3.5 m across.
- Weight: 5,190 kg (11,442 lbs.) at launch.
Orbit Quick Facts:
- Altitude: 705 kilometers (438 miles) above Earth’s surface
- Inclination: 98.5 degrees
- Period: 99 minutes (14 complete orbits per day)
- Ground track repeat: 16 days
- Equatorial crossing: 10:30 a.m., descending mode
- Operating instruments: ASTER, CERES, MODIS, MISR, and MOPITT are operating well. ASTER Short Wave Infrared (SWIR) data is unavailable.
- Current life expectancy: Terra has far exceeded its design life and has a strong chance of operating successfully into the early 2020s. Terra began drifting in February of 2020. Read more about Terra’s drifting.
- Current systems issues: None.
- Processed Terra data are available through several NASA data centers.