LANDSAT 7 is an American sun-synchronous remote sensing spacecraft that was launched by a Delta 2 rocket from Vandenberg AFB at 18:32 UT on 1999 April 15. Initial orbital parameters were period 98.4 min, apogee 698 km, perigee 669 km, and inclination 98.2 deg.
Landsat 7 continued the long-term earth observation Landsat program begun in 1972. Landsat 7 was a joint project between NASA, NOAA, and the US Geological Survey to obtain continuous high-resolution imagary of the earth's surface for environmental monitoring, disaster assessment, land use and regional planning, cartography, range management, oil and mineral exploration. Under the Land Remote Sensing Act of 1992 (PL 102-555), the Landsat program returned to the US Government and responsibilities assigned to NASA, NOAA, and the USGS. The Landsat 7 carried one instrument: (the Enhanced Thematic Mapper Plus (ETM+) The ETM+ was an improved version of the ETM on Landsat 6. The instrument provided improved spatial resolution. The Landsat 7 spacecraft provided improved ephemeris and attitude determination. The Landsat 7 spacecraft was built by Lockheed Martin Missiles and Space.
The 2,200-kg (including fuel) spacecraft carries an eight-band scanning radiometer (ETM+) to image the Earth, covering the overall wavelength range of 0.45 to 12.5 microns. (The eighth band covers a panchromatic range of 0.52 to 0.90 microns.) The resolution of the maps is 30 meters, except for the panchromatic band where it is 15 meters. The swath width of the pictures is 185 km, with repeated coverage of the same terrain after 233 orbits (=16 days). An onboard solid state memory can hold up to 375 gigabytes of images, so that full global coverage can be ensured. The mapping sectors remain as 10 AM +/- 15 min for all passes.
Facts in Brief
Launch Date: 1999-04-15
Launch Vehicle: Delta II 7920
Launch Site: Vandenberg AFB, United States
Mass: 2200.0 kg
Nominal Power: 1550.0 W