NASA SATELLITES TO PROBE ICE CAPS, OCEAN WINDS AND BIRTH OF STARS

11/28/2002
Publication: Agence France Presse English
Author: Not specified


Next month, three US satellites will blast off on missions to study the polar ice caps, the ocean winds and the birth of stars in the deepest recesses of outer space, NASA officials said.

The first satellite, aptly named ICESat (Ice, Cloud and land Elevation Satellite), will use a sophisticated laser to measure the thickness of the polar ice caps, especially whether they grow or shrink, over the Antarctic and Greenland.

ICESat will also provide valuable information on the sparse vegetation near the poles.

The onboard laser will fire 40 times per second, with each return beam giving a precise altitude measurement for the object it bounces off.

"This mission will provide revolutionary insight into changes in ice and the role ice plays in our Earth system, using a spaceborne laser to look at the topography of ice both in the Antarctic and Greenland, " National Aeronautics and Space Administration Associate Administrator for Earth Science Ghassem Asrar announced Tuesday at NASA headquarters.

"This information will help scientists determine whether the polar ice sheets are growing or shrinking, and how the ice masses may change under future climate conditions," he added.

ICESat will blast off into orbit December 19, at 7:45 pm (0045 GMT, December 20) from Vandenberg Air Force Base in California. It will settle at an altitude of some 600 kilometers (373 miles) above the Earth. NASA will use the same launch vehicle to place another satellite in orbit to study the formation of stars.

Called CHIPS (Cosmic Hot Interstellar Plasma Spectrometer), the suitcase size satellite carries a spectrometer to study very hot, low density gas in the far reaches of the cosmos.

Scientists believe the seemingly empty space between the stars contains the seeds of future stars. All the stars we are able to see are believed to have been formed from the same interstellar gas as it cooled, but the actual birth process of a star continues to be one of astrophysics' most intriguing mysteries.

CHIPS weighs in at 60 kilograms (132 pounds) and will sit in an orbit 590 kilometers (367 miles) above the Earth. It will have a lifespan of approximately one year.

NASA's third satellite will measure the speed and directions of the winds the whip over our oceans.

SeaWinds, as the satellite is called, will be launched by the Japanese space agency along with the Japan's Advanced Earth Observing Satellite II (Adeos II) on December 13, at 8:31 am (1331 GMT) from the Tanegashima space center.

"Winds play a major role in every aspect of Earth's weather. They directly affect the turbulent exchanges of heat, moisture and greenhouse gases between Earth's atmosphere and the ocean that drive ocean circulation and climate," said Asrar.

"The SeaWinds instrument will provide a critical tool for improving weather forecasting, detecting and monitoring severe marine storms, identifying subtle changes in the global climate and better understanding global weather abnormalities, such as El Nino and La Nina," he added.