CryoSat

CryoSat mission overview

CryoSat-2

The first is to acquire accurate measurements of the thickness of floating sea ice so that annual variations can be detected. The second is to survey the surface of ice sheets accurately enough to detect small changes.
 
CryoSat-2's radar altimeter is based on heritage from existing instruments, but with several major enhancements designed to improve measurements of icy surfaces. Because of its operations in SAR and Interferometric modes, the altimeter is called SIRAL (SAR Interferometric Radar Altimeter). CryoSat-2 is orbiting Earth at an unusually high inclination, reaching latitudes of 88° north and south.
 
 

	Measuring the freeboard of sea ice

CryoSat-2 will determine the thickness of floating sea ice by measuring the freeboard of ice floes; that is the height by which the ice extends above the water surface. This technique has been demonstrated with the ERS-1 radar altimeter, but this instrument, as with all conventional radar altimeters, is hampered by its relatively low spatial resolution of about 5 km. CryoSat-2 will achieve improved spatial resolution of 250 m in the along-track direction using the Synthetic Aperture technique.
 
 

CryoSat measuring ice sheet topographic surfaces.

The first returning energy in the radar echo comes from the part of the Earth's surface closest to the satellite. Over sea ice (and ocean) this point is directly below the satellite, but on sloping surfaces, such as those found around the edges of ice sheets, this nearest point can be anywhere. CryoSat-2 is able to pin down the location of the echo in the fore- and aft-direction by using its SAR capability, but to resolve left and right an additional feature is needed. Over these sloping surfaces CryoSat-2 operates in the SAR-Interferometry mode, which provides the key measurements of the angle of arrival and thus the pin-pointed source of the echo.
 
 

CryoSat -2 overview   Launched 8 April 2010 Mission duration Minimum 3 years Orbit LEO, non Sun-synchronous - Altitude 717 km - Inclination 92 deg - Repeat cycles 369 days with 30 day sub-cycle Payload SIRAL (SAR/Interferometric Radar Altimeter)   DORIS receiver   Laser retroreflector   Star-trackers (3) Mass 720 kg (incl 37 kg fuel) Dimensions 4.60 x 2.4 x 2.2 m Launch provider International Space Company Kosmotras Launcher Russian/Ukrainian Dnepr based on SS-18 intercontinental ballistic missile

 
 
Mission milestones

June 2011
First CryoSat sea-ice map of the Arctic presented at Le Bourget air show

April-May 2011
CryoSat validation campaign takes place in the Arctic

1 February 2011
CryoSat data open to all

November 2010
CryoSat goes live

October 2010
End of commissioning phase

July 2010
First data released to selected scientists for calibration and validation

8 April 2010
CryoSat-2 launched on 8 April at 15:57 CEST

7 April 2010
Russian State Commission give go-ahead to launch on 8 April at 15:57 CEST

19 March 2010
New launch date of 8 April announced

19 February 2010
Announcement that launch date of 25 February is delayed

January 2010
CryoSat shipped to Baikonur, Kazakhstan to begin launch campaign

September 2009
February 2010 target launch date announced

August 2009
Ground segment declared ready

February 2008
Prime instrument SIRAL rebuilt

February 2007
Critical Design Review passed

24 February 2006
ESA receives the green light from its Member States to build and launch a CryoSat recovery mission, CryoSat-2.

8 October 2005
First CryoSat mission lost due to an anomaly in the launch sequence.

 
 
 
Last update: 21 June 2011

•	CryoSat (http://www.esa.int/SPECIALS/Cryosat/index.html)
•	Track CryoSat-2 (http://www.esa.int/esaLP/SEMNKR1PLFG_LPcryosat_0.html)
•	Access CryoSat data (http://earth.esa.int/cryosat)
More information
•	CryoSat - ESA's ice mission (BR-276) (http://esamultimedia.esa.int/multimedia/publications/BR-276/pageflip.html)
•	CryoSat - Die ESA eismission (BR-199) (http://esamultimedia.esa.int/docs/Cryosat/CryoSat-Broschuere-Deutsch-Februar-2010.pdf)
Videos from the Arctic
•	CryoSat ground validation campaign (http://multimedia.esa.int/Videos/2011/06/Cryosat-Ground-validation-campaign)
•	CryoSat accuracy key to users (http://multimedia.esa.int/Videos/2011/06/Cryosat-accuracy-key-to-users)
•	CryoSat Earth Explorers and Greenland (http://multimedia.esa.int/Videos/2011/06/Cryosat-Earth-explorers-and-Greenland)
•	Greenland camp receives Dutch HRH Prince of Orange (http://multimedia.esa.int/Videos/2011/05/CryoSat-Greenland-camp-receives-Dutch-HRH-Prince-of-Orange)
Related links
•	EADS-Astrium (http://www.astrium.eads.net/)
•	Thales Alenia Space - SIRAL (http://www.thalesgroup.com/Case_Studies/CaseStudy_space_SIRAL/?pid=1576)
•	IABG (http://www.iabg.de/index_en.php)
•	Kosmotras (http://www.kosmotras.ru/en/)
•	International Laser Ranging Service (ILRS) (http://ilrs.gsfc.nasa.gov/)
•	German CryoSat project office (http://www.cryosat.de)
•	ICESat mission (http://icesat.gsfc.nasa.gov/)
Understanding the polar environment
•	Polar View (http://www.polarview.org/)
•	International Polar Year (http://www.ipy.org/)
•	Centre for Polar Observation and Modelling (CPOM) (http://www.cpom.org/)