27642 - ICESAT

ICESAT is an American (NASA) Earth Observing System spacecraft that was launched by a Delta 2 rocket from Vandenberg AFB at 00:45 UT on 2003 January 13. It carries a single instrument, GLAS (Geoscience Laser Altimeter System) which enables accurate surface level measurements of ice sheets. GLAS transmits four-nanosecond-wide pulses, one at 1,064 nm and another at 532 nm wavelengths, at a rate of 40 pulses/s. The infrared pulses are reflected from the ice surfaces, and the green line pulses from the atmosphere. The reflected pulses are collected by an 80-cm diameter telescope. The precise altitude of the spacecraft is determined with the help of the GPS constellation of satellites. Ice surface variations in Greenland and Antarctica are important predictors of global warming.

The raw and analyzed data will be archived at the National Snow and Ice Data Center, affiliated with the University of Colorado and the NOAA, Boulder, CO.

ICESat is a part of NASA's Earth Observing System. Its primary objectives are to determine the mass balance of the polar ice sheets and their contributions to global sea level change and to obtain essential data for prediction of future changes in ice volume and sea-level. Secondary objectives are to measure cloud heights and the vertical structure of clouds and aerosols in the atmosphere, to map the topography of land surfaces, and to measure roughness, reflectivity, vegetation heights, snow-cover, and sea-ice surface characteristics.

Alternate Names

Ice, Cloud, and Land Elevation Satellite

Facts in Brief

Launch Date: 2003-01-13
Launch Vehicle: Delta II
Launch Site: Vandenberg AFB, United States
Nominal Power: 350.0 W