Copernicus Anthropogenic Carbon Dioxide Monitoring (CO2M) Mission

Quick facts

Overview

Summary

Mission Capabilities

CO2M will carry three primary instruments designed to accurately measure atmospheric greenhouse gases (GHGs). The main payload is an Imaging Spectrometer (CO2I/NO2I) that will allow measurements to provide carbon dioxide (CO₂), methane (CH₄), and nitrogen dioxide (NO₂) at relatively high spatial resolution to support the estimation of anthropogenic emissions. The first auxiliary payload is a Multi-Angle Polarimeter (MAP), which will allow the characterisation of aerosols by measuring the polarisation of reflected light from multiple angles. These observations will allow to accurately correct for light path distortions caused by aerosol scattering, which will improve the retrieval of CO₂ and CH₄ in presence of aerosol up to an aerosol optical depth of 0.5 (or possibly higher) within the stringent requirement for maximum systematic error (<0.12%). The second auxiliary payload is a CLoud IMager (CLIM), which will detect the presence of low and high-altitude clouds and enable it to remove cloud-contaminated data from the retrieval.

Performance Specifications

CO2I/NO2I is a push-broom imaging spectrometer designed to measure CO₂ at 0.7 ppm and CH₄ at 10 ppb precision and NO₂ with a spatial resolution of 2 km over a swath of at least 250 km. It will observe top-of-atmosphere radiances in the visible (405–490 nm), near infrared (747–773 nm) and two shortwave infrared (1590–1675 nm, 1990–2095 nm) spectral bands. CLIM will detect clouds using three spectral bands (670 nm, 753 nm, and 1370 nm) at a spatial resolution of 0.4 km × 0.4 km, ensuring that cloud-contaminated pixels are excluded from the CO₂ and CH₄ retrievals. MAP will measure radiance in six narrow bands between 410 nm and 865 nm, in three polarisation directions and in 40 angles over an angular range of +/- 60 degrees, which will allow characterisation of aerosol. MAP has additionally one band at 753 nm that is common to all instruments allowing accurate spatial co-registration.

The CO2M satellites will fly in a phased Sun-synchronous orbit at an altitude of approximately 735 km and an orbital inclination of 97.7°, with local time at descending node of 11:30. While a single satellite will provide an 11-day revisit cycle at the equator, deploying two satellites reduces this to 6 days, and three operating together will achieve full global coverage approximately every 3.5 days.

Space and Hardware Components

OHB System AG is the prime contractor for developing the CO2M satellites. The platform is based on the OHB standard EO platform and includes six radiator panels, a stacked propulsion tank configuration, a decentralised data handling system, separate units for power conditioning and distribution, and a single-wing solar array. The payload is thermally and mechanically isolated from the platform to ensure optimal performance. Science data handling is managed via a Wizard link for the CO2I/NO2I spectrometer and SpaceWire links for the MAP and CLIM instruments, with 60 Mbps peak data rates per link.

The CO2M payloads will generate substantial data volumes per orbit: approximately 400 Gbit for CO2I/NO2I, 200 Gbit for MAP, and 100 Gbit for CLIM. These instruments are developed by a consortium of European partners, which is led by Thales Alenia Space (France) as the prime contractor. OIP Sensors is developing the CLIM instrument, which is derived from the PROBA-V instrument concept.

Overview

The Copernicus Anthropogenic Carbon Dioxide Monitoring (CO2M) Mission is a major European initiative developed to monitor and quantify carbon dioxide (CO₂), methane (CH₄), and nitrogen dioxide (NO₂) emissions, specifically from human activities, on a global scale. Developed by ESA in collaboration with the European Commission (EC) and the European Organisation for the Exploitation of Meteorological Satellites (EUMETSAT), as part of the Copernicus Sentinel Expansion missions for the European Union, CO2M aims to enable actionable, transparent data to support climate policy, track progress on emission reductions, and verify national commitments under the Paris Agreement. The objective of the mission is to provide the European Union with an operational capacity that contributes to the global monitoring of anthropogenic CO₂ emissions. 1) 2) 3)

To ensure comprehensive and frequent global coverage, the mission will consist of up to three identical satellites: CO2M-A, CO2M-B, and CO2M-C. The satellites will each carry three primary instruments: a combined CO₂ and NO₂ Imaging Spectrometer (CO2I/NO21), a CLoud IMager (CLIM), and a Multi-Angle Polarimeter (MAP). Combined, these instruments will provide high-resolution, global mapping of atmospheric CO₂ and CH₄ concentrations at high accuracy, enabling the identification of emission hotspots and trends. 4)

CO2M will enable the first systematic, high-precision, global tracking of anthropogenic CO₂ emissions. This capability is crucial for verifying emission inventories, supporting climate negotiations, and guiding effective climate action. The data products generated by CO2M will enable users to distinguish human-induced emissions from natural fluxes and track emission trends in near real-time. This capability is essential for transparency and accountability in climate policy implementation across Europe and globally.

Spacecraft

OHB System AG (Bremen, Germany) is the prime contractor responsible for developing the CO2M satellites. Thales Alenia Space (Cannes, France) is the prime contractor of OHB for the CO2M payload, and will also develop two of the mission's core instruments: the spectrometer and MAP. The satellites will be based on OHB’s standard EO satellite platform. OHB has a long history in European satellite development, developing spacecraft for missions such as SAR-Lupe, EnMAP, and the Galileo navigation constellation. 5)

All platform subsystems including the structure, avionics, power, and attitude control are developed under OHB responsibility. Each CO2M spacecraft is 3-axis stabilised, with a launch mass of approximately 2000 kg, and utilises a single-wing solar array configuration. 6) 7) 8) 9) 

The Common Platform is engineered for flexible, high-performance EO missions. Its core structure is a lightweight aluminium-honeycomb panel design supported by an internal shear frame. This configuration offers both stiffness and modularity for equipment mounting. External faces are covered in multi-layer insulation (MLI) and radiator panels to manage waste heat. The heat generated by internal systems is conducted via embedded heat pipes to radiators mounted on the top or payload side of the spacecraft. Critical components are further regulated using small heaters to maintain operational temperatures.

The propulsion subsystem is a monopropellant hydrazine design, using two stacked central propellant tanks housed within the core module. This feeds eight thrusters mounted inside the LVA ring for orbit insertion and maintenance manoeuvres.

The platform also incorporates a decentralised data handling architecture, separating the power conditioning and distribution unit (PCDU) from the payload power distribution unit (PPDU). This setup enables efficient and scalable power management.

Orbit

The CO2M satellites will be deployed into a Sun-synchronous orbit (SSO) at an altitude of approximately 735 km and an inclination of 97.7°. This descending orbit maintains a consistent local time of descending node (LTDN) at 11:30, ensuring uniform solar illumination conditions for observations. 9) 10)

The satellites will be phased into a constellation to provide optimal coverage and revisit time. Operating individually, a single CO2M satellite will achieve an 11-day revisit cycle; with two satellites, this is halved, and a three-satellite configuration will provide full global coverage every 3–4 days at the equator.

Mission Status

• January 28, 2025: ESA and OHB System AG signed a €175.5 million contract for the development of a third CO2M satellite (CO2M-C), enhancing the Copernicus mission to monitor greenhouse gas emissions. This addition will improve global coverage and measurement frequency, reducing the revisit time to approximately 3 days with all three satellites in orbit. 11)
• January 28, 2025: Thales Alenia Space signed an €88 million contract amendment with OHB System AG to develop the payload for the third CO2M satellite, building upon their work on the first two satellites. 12)
• September 30, 2024: Researchers at Fraunhofer IOF completed and delivered the first flight-ready disperser, a critical optical component for the CO2M spectrometers, enabling high-precision greenhouse gas measurements. 13)
• May 23, 2022: CO2M is progressing as ESA has authorised prime contractor OHB to continue developing the first satellite (CO2M-A) and start production on the second satellite (CO2M-B).14)

• January 24, 2022: ESA shared European plans and expertise on measuring carbon dioxide and methane from space with the U.S. President's Council of Advisors on Science and Technology (PCAST). Yasjka Meijer, ESA mission scientist for CO2M, made recommendations on improving efforts to measure and monitor greenhouse gas emissions. 15)
• November 10, 2021: ESA is rigorously testing the CO2M Mission satellite at its test centre in the Netherlands. The satellite's structural model is undergoing tests to ensure its mechanical integrity and ability to withstand launch vibrations. 16)

• July 31, 2020: ESA and OHB System AG have signed a €445 million contract to build the first two satellites for the CO2M mission. OHB will lead the industrial consortium, overseeing the development of the satellite platforms. Thales Alenia Space will supply CO2M’s NIR and SWIR spectrometer for measuring CO₂ emissions. The contract for the CO2M mission is the first to be signed following ESA’s industrial committee approval to proceed with the development of six new Copernicus high-priority missions earlier this month. 17) 18)
• July 3, 2020: ESA's industrial policy committee has approved contracts totalling €2.55 billion to develop six new Copernicus satellite missions. Each mission comprises two satellites, a development unit, and a recurrent unit. The project is co-funded by the EU and ESA Member States. 19)

Sensor Complement

Combined CO₂ and NO₂ Imaging Spectrometer (CO2I/NO2I)

CO2I/NO2I is the primary instrument onboard CO2M. It is a push‑broom nadir‑scanning imaging spectrometer designed to measure column concentrations of anthropogenic GHGs. Its primary targets are the total column of CO₂ (precision 0.7 ppm) and CH₄ (precision 10 ppb), while also quantifying NO₂ plumes to help identify and attribute emission sources. The instrument builds on the heritage of earlier GHG missions such as NASA’s OCO‑2 and JAXA’s GOSAT. 7) 9) 20)

CLoud IMager (CLIM)

CLIM is a three‑band wide‑swath imager derived from the PROBA‑V heritage. Its sole purpose is to detect clouds (liquid water and cirrus) in the CO2I/NO2I pixels so that cloudy scenes can be flagged or removed. CLIM is a push‑broom camera that acquires radiances in three fixed spectral bands: 670 nm, 753 nm, and 1370 nm. These wavelengths are chosen for their sensitivity to water clouds and cirrus ice. 7) 9) 20)

Multi-Angle Polarimeter (MAP)

MAP is a multi‑angle spectro‑polarimetric imager that measures polarised reflected sunlight to characterise aerosols. Its data are used to correct CO₂/CH₄ retrievals for aerosol scattering. MAP observes each scene from many viewing angles (up to 40 angles) and polarisations, providing the degree of linear polarisation in each of six narrow spectral bands plus a reference band. MAP is a rotated push‑broom camera with polarisation analysers, building on the heritage of the POLDER/3MI family of multi‑angle polarimeters. 7) 9) 20)

Ground Segment

The ground segment for the CO2M mission forms a critical part of the system, enabling the transformation of satellite observations into high-quality, usable data products. EUMETSAT, in close partnership with ESA, is responsible for the operational aspects of this segment, including product validation and continuous data quality monitoring. 21)

At the core of the ground segment is the Payload Data Processing Segment (PDPS), developed and operated by EUMETSAT. The PDPS manages the day-to-day processing of data received from the CO2M satellites. Table 5 outlines the key details of the data levels the PDPS generates. The system is designed to deliver Level 1 and Level 2 products to users within 24 hours of observation, ensuring timely access to critical environmental information. 9)

EUMETSAT and ESA will jointly oversee the validation process, which relies heavily on high-precision ground-based reference measurements. In particular, spectrometers within the TCCON (Total Carbon Column Observing Network) and COCCON (COllaborative Carbon Column Observing Network) networks provide essential validation data, allowing comparisons between satellite-derived and ground-truth atmospheric observations. 21)

Table 6 outlines the primary responsibilities of the ground segment components, including data acquisition, processing, validation, and dissemination.

Copernicus Greenhouse Gas Monitoring and Verification Support (GHG MVS) Capacity

The Copernicus Greenhouse Gas Monitoring and Verification Support (GHG MVS) capacity is being developed by the European Centre for Medium-Range Weather Forecasts (ECMWF) under the Copernicus Atmosphere Monitoring Service. It will combine high-precision satellite data, including from the CO2M mission, with in-situ observations and modelling to quantify and attribute anthropogenic greenhouse gas emissions. The system aims to reduce uncertainties in fossil-fuel CO₂ estimates at local to regional scales, providing the EU with an independent, operational capacity to evaluate climate policies, track progress toward emission-reduction targets, and support the Paris Agreement’s global stocktake process. 3) 23) 24)

See MVS for more details.

References

1) SPIE Digital Library, “The Copernicus CO2M mission for monitoring anthropogenic carbon dioxide emissions,” 2021, URL: https://www.spiedigitallibrary.org/conference-proceedings-of-spie/11852/2599613/The-Copernicus-CO2M-mission-for-monitoring-anthropogenic-carbon-dioxide-emissions/10.1117/12.2599613.full

2) EUMETSAT, “CO2M,” URL: https://www.eumetsat.int/co2m

3) ESA, “CO2M Mission Requirements Document (MRD) v3.0,” 2020, URL: https://esamultimedia.esa.int/docs/EarthObservation/CO2M_MRD_v3.0_20201001_Issued.pdf

4) Atmospheric Measurement Techniques, “The Copernicus CO2M mission: instrument concept and retrieval performance,” 2021, URL: https://amt.copernicus.org/articles/14/1167/2021/

5) ESA, “CO2M Mission Requirements Document v3.0,” 1 October 2020, URL: https://esamultimedia.esa.int/docs/EarthObservation/CO2M_MRD_v3.0_20201001_Issued.pdf

6) OHB, “CO2M – a greenhouse gas hunter takes shape,” URL: https://www.ohb.de/en/magazine-garden/co2m

7) Thales Group, “Thales Alenia Space to partner with OHB System to build Copernicus CO2M mission,” URL: https://www.thalesgroup.com/en/worldwide/space/press-release/thales-alenia-space-partner-ohb-system-build-copernicus-co2m

8) Copernicus SentiWiki, “CO2M,” URL: https://sentiwiki.copernicus.eu/web/co2m

9) OHB, “OHB System Satellite Platforms 2019,” URL: https://www.ohb.de/fileadmin/ohb/Downloads/190603_OHB-System_Satellite_Platforms_2019-05.pdf#:~:text=Energy%20Supply%20Average%20Power%20Payload%3A,Band%3A%204%20Gbps

10) SPIE Digital Library, “Copernicus CO2M – status of the mission for monitoring anthropogenic CO2 emissions,” 2023, URL: https://www.spiedigitallibrary.org/conference-proceedings-of-spie/12777/127774I/Copernicus-CO2M--status-of-the-mission-for-monitoring-anthropogenic/10.1117/12.2690839.full

11) ESA, “Launches secured for five Sentinel satellites,” URL: https://www.esa.int/Applications/Observing_the_Earth/Copernicus/Launches_secured_for_five_Sentinel_satellites

12) OHB, “OHB and ESA signed a contract for the third Copernicus CO2M satellite,” URL: https://www.ohb.de/en/news/ohb-and-esa-signed-a-contract-for-the-third-copernicus-co2m-satellite

13) Thales Alenia Space, “Thales Alenia Space to develop payload for third satellite of Copernicus CO2M mission,” URL: https://www.thalesaleniaspace.com/en/press-releases/thales-alenia-space-develop-payload-third-satellite-copernicus-co2m-mission

14) Fraunhofer IOF, “Disperser delivered for ESA CO2M mission,” 2024, URL: https://www.iof.fraunhofer.de/en/pressrelease/2024/ESA-CO2M-mission-Disperser-delivered.html

15) ESA, “Full steam ahead for carbon dioxide monitoring mission,” URL: https://www.esa.int/Applications/Observing_the_Earth/Copernicus/Full_steam_ahead_for_carbon_dioxide_monitoring_mission

16) ESA, “ESA supports the White House on greenhouse gas monitoring,” URL: https://www.esa.int/Applications/Observing_the_Earth/Copernicus/ESA_supports_the_White_House_on_greenhouse_gas_monitoring

17) ESA, “Carbon dioxide monitoring satellite given the shakes,” URL: https://www.esa.int/Applications/Observing_the_Earth/Copernicus/Carbon_dioxide_monitoring_satellite_given_the_shakes

18) ESA, “Contract signed to build Europe’s carbon dioxide monitoring mission,” URL: https://www.esa.int/Applications/Observing_the_Earth/Copernicus/Contract_signed_to_build_Europe_s_carbon_dioxide_monitoring_mission

19) ESA, “Mission Requirements Document – CO2M,” 27 September 2019, URL: https://esamultimedia.esa.int/docs/EarthObservation/CO2M_MRD_v2.0_Issued20190927.pdf

20) ESA, “Contracts awarded for development of six new Copernicus missions,” URL: http://www.esa.int/Applications/Observing_the_Earth/Copernicus/Contracts_awarded_for_development_of_six_new_Copernicus_missions

21) CEOS, “Status of Copernicus CO2 Mission – Y. Meijer,” 2 May 2018, URL: https://ceos.org/document_management/Virtual_Constellations/ACC/Meetings/AC-VC-14/Wednesday%20May%202/1200_Status%20Copernicus%20CO2%20Mission%20YMeijer%20v20180502-for%20distribution.pdf#:~:text=

22) EUMETSAT, “CO2M Central Ground-Based Data Processing Facility – Science Support,” URL: https://www.eumetsat.int/co2m-central-ground-based-data-processing-facility-science-support 

23) Copernicus Atmosphere Monitoring Service, “Greenhouse gas services,” URL: https://atmosphere.copernicus.eu/ghg-services

24) ESA, “CO2M Mission Requirements Document (MRD) v3.0,” 2020, URL:  https://esamultimedia.esa.int/docs/EarthObservation/CO2M_MRD_v3.0_20201001_Issued.pdf

25) Kuhlmann G., Henne S., Meijer Y., and Brunner D., Quantifying CO2 Emissions of Power Plants With CO2 and NO2 Imaging Satellites, Front. Remote Sens., vol. 2, https://doi.org/10.3389/frsen.2021.689838, 2021.

26) Meijer Y.J., E. Andersson, H. Boesch, O. Dubovik, S. Houweling, J. Landgraf, R. Lang and H. Lindqvist, Editorial: Anthropogenic emission monitoring with the Copernicus CO2 monitoring mission. Front. Remote Sens. 4:1217568. doi: 10.3389/frsen.2023.1217568, 2023

27) Rusli, S. P., Hasekamp, O., aan de Brugh, J., Fu, G., Meijer, Y., and Landgraf, J.: Anthropogenic CO2 monitoring satellite mission: the need for multi-angle polarimetric observations, Atmos. Meas. Tech., 14, 1167–1190, https://doi.org/10.5194/amt-14-1167-2021, 2021.

28) Meijer, Y.J., Who is really cutting emissions? These satellites will tell us, Supplement to The European Magazine, https://the-european.eu/story-45883/who-is-really-cutting-emissions-these-satellites-will-tell-us.html, 2025

Films and Animations

• Tracking human emissions from space, https://www.esa.int/ESA_Multimedia/Videos/2023/12/Tracking_human_emissions_from_space 
• Animation of EMPA/ECMWF/ESA on Copernicus CO2 Monitoring mission, https://www.youtube.com/watch?v=ZiFEe7IN2Go 
• Global Stocktake: how space drives climate action, https://www.esa.int/ESA_Multimedia/Videos/2023/11/Global_Stocktake_how_space_drives_climate_action