European Space Agency (ESA) can breathe with relief
now when CryoSat-2 satellite was successfully launched and shot into the
polar orbit from Baikonur Cosmodrome on 8th April 2010. CryoSat-2
measures ice thickness over land and oceans. These data are invaluable for
the estimates of total ice mass on Earth. CrySat-2 is described as "a
hi-tech mission showing what European collaboration can achieve".
ESA’s Earth Explorer CryoSat mission is dedicated to precise monitoring of
the changes in the thickness of marine ice floating in the polar oceans and
variations in the thickness of the vast ice sheets that overlay Greenland
and Antarctica. CryoSat-2 replaces the original CryoSat satellite that was
lost in 2005 owing to a launch failure. The mission objectives however
remain the same.CryoSat is in fact a SAR
Interferometric Radar Altimeter (SIRAL), supported by Doppler Orbit and
Radio Positioning Integration by Satellite (DORIS) and Laser Retro-Reflector
(LRR) for precision orbit determination. It is positioned on the orbit of
mean altitude of 717 km and inclination of 92 degrees (low earth, polar,
non-Sun-synchronous). The real data are transmitted to ESA ground station in
Kiruna, Sweden. CryoSat-2 mission is planned for 3 years with a possibility
of further extension for another 2-year period.
For some years now, satellites such as ESA’s Envisat
have been mapping the extent of ice cover and have shown that annual average
Arctic sea-ice extent has shrunk by 2.7% per decade since 1978. While these
observations on ice extent provide invaluable data, this is only part of the
picture. In order to understand fully how climate change is affecting these
sensitive regions, there remains an urgent need to determine exactly how the
thickness of land and sea ice is changing. CryoSat is Europe's first mission
to address this issue.
CryoSat-2 carries sophisticated technologies to measure changes at the
margins of the vast ice sheets that overlay Greenland and Antarctica and
marine ice floating in the polar oceans. By accurately measuring thickness
change in both types of ice, CryoSat-2 will provide information to complete
the picture and lead to a better understanding of the role ice plays in the
Earth system.
Launched on 8 April 2010, CryoSat-2 is in a highly inclined polar orbit,
reaching latitudes of 88° north and south, to maximise its coverage of the
poles. Its main payload is an instrument called Synthetic Aperture
Interferometric Radar Altimeter (SIRAL). Previous radar altimeters have been
optimised for operations over the ocean and land, but SIRAL is the first
sensor of its kind designed for ice.
ESA's Earth Explorers are launched in direct response
to issues identified by the scientific community and aim to improve our
understanding of how the Earth system works and the effect that human
activity is having on natural processes.
Source: European Space Agency (http://www.esa.int/esaCP/index.html)
Contacts: Richard Francis, ESTEC (ESA's European Technology Centre) -
CrySat-2 Project Manager; Duncan Wingham, University College London (UCL) -
CryoSat Lead Investigator
Read more:
Is-satelliten er tilbake (in Norwegian)
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Successful launch of CryoSat-2 on 8th April 2010 from Bakonur Cosmodrome
(photo: ESA)
CryoSat-2 (illustration: ESA)
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