World Library  
Flag as Inappropriate
Email this Article


Article Id: WHEBN0001931235
Reproduction Date:

Title: CryoSat  
Author: World Heritage Encyclopedia
Language: English
Subject: CryoSat-1, CryoSat-2, Soil Moisture and Ocean Salinity, Living Planet Programme, Space radars
Collection: European Space Agency, Space Radars, Spaceflight
Publisher: World Heritage Encyclopedia


CryoSat is an ESA programme to monitor variations in the extent and thickness of polar ice through use of a satellite in low Earth orbit. The information provided about the behaviour of coastal glaciers that drain thinning ice sheets will be key to better predictions of future sea level rise. The CryoSat-1 spacecraft was lost in a launch failure in 2005, however the programme was resumed with the successful launch of a replacement, CryoSat-2, launched on 8 April 2010.[1][2]

CryoSat is operated from the European Space Operations Centre (ESOC) in Darmstadt, Germany.


  • Description 1
  • Launch failure of original cryosat 2
  • See also 3
  • References 4
  • External links 5


CryoSat's primary instrument is SIRAL (SAR / Interferometric Radar Altimeter). SIRAL operates in one of three modes, depending on where (above the Earth's surface) CryoSat was flying. Over the oceans and ice sheet interiors, CryoSat operates like a traditional radar altimeter. Over sea ice, coherently transmitted echoes are combined (synthetic aperture processing) to reduce the surface footprint so that CryoSat could map smaller ice floes. CryoSat's most advanced mode is used around the ice sheet margins and over mountain glaciers. Here, the altimeter performs synthetic aperture processing and uses a second antenna as an interferometer to determine the across-track angle to the earliest radar return. This provides the exact surface location being measured when the surface is sloping.

The original CryoSat was proposed in 1998 by Duncan Wingham of University College London. The satellite's planned three-year mission was to survey natural and human driven changes in the cryosphere on Earth. It was designed to provide much more accurate data on the rate of change of the surface elevation of the polar ice sheets and sea ice thickness. It was the first ESA Earth Sciences satellite selected through open, scientific competition.[3] It was destroyed on launch October 8, 2005. The existing satellite is therefore CryoSat-2, but the mission is still known as simply CryoSat.[4]

Although largely the same as the original satellite a number of key improvements were included in CryoSat-2. The most significant was the decision to provide a fully duplicated payload to enable the mission to continue if a fault caused the loss of the SIRAL radar, but there were many other changes "under the hood". Some of these were caused by obsolescence in the original design, some improved reliability and others made the satellite easier to operate. Despite all the changes the mission remains the same and the performance, in terms of measurement capability and accuracy, remains the same. As of 14 January 2010, the launch was scheduled for February 25, 2010 with a Dnepr rocket from the Baikonur Cosmodrome,[5] but this was delayed. The CryoSat 2 launched on April 8, 2010 at 13:57 UTC.[6][7]

For positioning purposes, CryoSat included a DORIS receiver, a laser retroreflector and three star trackers.

The ERS-1 and ERS-2 satellites were precursors that tested the techniques used by CryoSat.

Launch failure of original cryosat

CryoSat was launched from the Plesetsk Cosmodrome in Russia on October 8, 2005, using a Rockot launcher. (Rockot is a modified SS-19 rocket which was originally an ICBM designed to deliver nuclear weapons, but which Russia is now eliminating in accordance with the START treaties.) According to Mr. Yuri Bakhvalov, First Deputy Director General of the Khrunichev Space Centre, when the automatic command to switch off the second stage engine did not take effect,[8][9] the second stage continued to operate until it ran out of fuel and as a consequence the planned separation of the third (Breeze-KM) stage of the rocket which carried the CryoSat satellite did not take place, and would thus have remained attached to the second stage. The upper rocket stages, together with the satellite, probably crashed in the Lincoln Sea.

Analysis of the error revealed that it was caused by faults in the programming of the rocket, which had not been detected in simulations.[10]

After the launch failure of CryoSat, ESA immediately started to plan a replacement CryoSat mission. This included securing the industrial team which had built the original, ordering parts which have a long delivery time and establishing a funding scheme within existing budgets. Due to the importance of the scientific goals of this satellite, there was enormous support for this, and the initial phases for CryoSat-2 were approved when ESA's Earth Observation Programme Board agreed to build a copy of the spacecraft on February 23, 2006.[11]

See also


  1. ^ Nature news brief The week in science dated April 15, 2010
  2. ^ European Space Agency article ESA confirms CryoSat recovery mission dated February 24, 2006
  3. ^ CPOM Website
  4. ^
  5. ^
  6. ^
  7. ^
  8. ^ "CryoSat Mission lost due to launch failure" (Press release). ESA. 8 October 2005. Retrieved 2007-03-12. 
  9. ^ "CryoSat Mission has been lost" (Press release). Eurockot Launch Service Provider. 8 October 2005. Retrieved 2007-03-12. 
  10. ^ "CryoSat crash by human failure" (in German). 22 December 2005. Retrieved 2007-03-12. 
  11. ^ Briggs, Helen (24 February 2006). "Go-ahead for Europe ice mission". BBC News. Retrieved 2007-03-12. 

External links

  • Cryosat rocket fault laid bare
  • CryoSat pages at ESA
  • CryoSat-2 page at ESA Spacecraft Operations
  • "Ice mission almost set for launch" – By Helen Briggs, BBC News, 22 July 2005
  • Why did Cryosat crash? Australian Broadcasting Company's The Lab Cryosat story
  • Cryosat-2: Scientists and Polar Explorers Collect Vital Support Data.
  • Nature article The salt flat with curious curves says "the salt flat is also being used for Envisat, a European satellite, and could be used to calibrate future orbiters such as Cryosat-2"

This article was sourced from Creative Commons Attribution-ShareAlike License; additional terms may apply. World Heritage Encyclopedia content is assembled from numerous content providers, Open Access Publishing, and in compliance with The Fair Access to Science and Technology Research Act (FASTR), Wikimedia Foundation, Inc., Public Library of Science, The Encyclopedia of Life, Open Book Publishers (OBP), PubMed, U.S. National Library of Medicine, National Center for Biotechnology Information, U.S. National Library of Medicine, National Institutes of Health (NIH), U.S. Department of Health & Human Services, and, which sources content from all federal, state, local, tribal, and territorial government publication portals (.gov, .mil, .edu). Funding for and content contributors is made possible from the U.S. Congress, E-Government Act of 2002.
Crowd sourced content that is contributed to World Heritage Encyclopedia is peer reviewed and edited by our editorial staff to ensure quality scholarly research articles.
By using this site, you agree to the Terms of Use and Privacy Policy. World Heritage Encyclopedia™ is a registered trademark of the World Public Library Association, a non-profit organization.

Copyright © World Library Foundation. All rights reserved. eBooks from Project Gutenberg are sponsored by the World Library Foundation,
a 501c(4) Member's Support Non-Profit Organization, and is NOT affiliated with any governmental agency or department.