CryoSat-2

CryoSat-2
Name	CryoSat-2
Operator	European Space Agency
Mission type	Earth observation
Mission duration	12 years (ongoing)
Launch date	8 April 2010
Launch vehicle	Rockot
Launch site	Plesetsk Cosmodrome
Manufacturer	EADS Astrium
Orbit reference	Geocentric orbit
Orbit periapsis	717 km
Orbit apoapsis	732 km
Orbit inclination	92.00°
Instruments	SAR/Interferometric Radar Altimeter (SIRAL)

CryoSat-2 CryoSat-2 is a European Space Agency Earth observation satellite designed to measure variations in the thickness of polar ice caps, sea ice, and glaciers using a specialized radar altimeter. It succeeded an earlier mission loss and entered orbit in April 2010, providing continuous high-resolution datasets used by agencies and research institutions across Europe, North America, and worldwide. The mission underpins studies in climate change, cryosphere dynamics, sea level rise, and polar oceanography.

Overview

CryoSat-2 was developed by European Space Agency in partnership with British National Space Centre priorities and built by EADS Astrium with contributions from Thales Alenia Space, RHEA Group, and national agencies including National Centre for Earth Observation, CNES, DLR, and NASA collaborators. The satellite carries the SAR/Interferometric Radar Altimeter instrument derived from technologies used on ERS-1, ERS-2, Envisat, and Jason-1 while incorporating lessons from the failed CryoSat launch. The mission supports programs such as Global Climate Observing System, IPCC assessments, and feeds data into portals operated by European Space Agency Climate Office and Copernicus-related services.

Mission Objectives

Primary objectives are to determine changes in thickness and mass balance of Greenland ice sheet, Antarctic ice sheet, and Arctic sea ice; to monitor glacier retreat in regions like Alaska, Patagonia, Himalaya, and Scandinavia; and to quantify contributions to global sea level rise. Secondary goals include supporting studies of permafrost dynamics in Siberia, mapping ice shelves such as Filchner-Ronne Ice Shelf and Ross Ice Shelf, and improving models used by groups like IPCC, National Oceanic and Atmospheric Administration, Met Office, National Snow and Ice Data Center, and Proudman Oceanographic Laboratory.

Spacecraft and Instruments

The core instrument, SIRAL, is a dual-frequency, phased-array radar altimeter operating in synthetic aperture radar (SAR) and interferometric modes to resolve cross-track slopes and surface roughness. SIRAL’s heritage traces to systems on CryoSat (original), ERS-2, and SARAL/AltiKa design principles. The platform includes subsystems from SEP, Sener, Astrium Satellites, and leverages onboard processors similar to those used on ENVISAT and ICEsat mission components. Ancillary instruments and subsystems include an on-board Star tracker from Sodern, an GPS receiver for precise orbit determination using networks like International GNSS Service, and thermal control units from RUAG.

Launch and Operations

Launched 8 April 2010 on a Rockot launcher from Plesetsk Cosmodrome with mission operations led by the European Space Agency’s ESRIN and ESOC centers. Ground segment operations coordinate data reception via stations such as Svalbard Satellite Station, Kiruna Station, Inuvik Tracking Station, and Svalbard Global Seed Vault-adjacent infrastructure for polar support. Flight operations used procedures developed after the CryoSat failure, incorporating enhanced mission assurance from UK Space Agency and industrial partners like Airbus Defence and Space. Orbital parameters place CryoSat-2 in a near-polar, sun-synchronous orbit enabling repeat passes over high latitudes.

Data Processing and Applications

CryoSat-2 data products are processed into levelled altimetry datasets (Level 1, Level 2, Level 3) by teams at CPOM (Centre for Polar Observation and Modelling), ESA Climate Office, Norwegian Polar Institute, and University of Leeds. The datasets integrate corrections from models and providers like ECMWF, EUMETSAT, USGS, NOAA, and Google Earth Engine for visualization. Applications include assimilation into ice-sheet models developed at University of Cambridge, MIT, Caltech, University of Colorado Boulder, and Scott Polar Research Institute; calibration of ICESat and ICESat-2 laser altimetry; support for shipping route planning by International Maritime Organization in Arctic waters; and validation of CMIP climate model outputs used by IPCC authors.

Scientific Results and Impact

CryoSat-2 has produced landmark regional and global estimates of polar ice mass change, revealing accelerating ice loss in Greenland, West Antarctica, and parts of East Antarctica, with implications for projections made by IPCC AR5 and later assessments. Results informed studies published by groups at University of Bristol, University of Edinburgh, Lamont–Doherty Earth Observatory, Potsdam Institute for Climate Impact Research, and Woods Hole Oceanographic Institution. CryoSat-2 enabled improved mapping of sea-ice freeboard for the Arctic Ocean and quantified thinning of seasonal and perennial ice, supporting operational forecasts at Met Office Hadley Centre and European Centre for Medium-Range Weather Forecasts. Cross-calibration with GRACE, GRACE-FO, and ICESat refined estimates of mass balance and contributed to improved sea level budgets used by Intergovernmental Panel on Climate Change authors.

Challenges and Anomalies

The mission faced early technical concerns after the original CryoSat launch failure; CryoSat-2 benefited from design reviews and enhanced quality assurance by European Space Agency and industry partners. Operational challenges included calibrating SIRAL over complex topography such as Patagonian Icefields and steep Himalayan glaciers, dealing with radio-frequency interference in polar regions monitored by International Telecommunication Union rules, and mitigating orbit maintenance issues requiring maneuvers planned at ESOC. Scientific limitations include temporal sampling constraints for fast-flowing outlet glaciers like Jakobshavn Glacier and Pine Island Glacier, and ambiguity in radar penetration over snow facies studied by teams at University of Washington and Scott Polar Research Institute.

Category:Earth observation satellites Category:European Space Agency satellites