Copernicus Sentinel-3C

History

Copernicus Sentinel-3C is a European Earth-observation satellite developed for the European Union's Copernicus programme. It continues the Sentinel-3 mission, which systematically observes Earth's oceans, land, ice and atmosphere.

The spacecraft was designed and developed by the European Space Agency on behalf of the European Commission, with Thales Alenia Space serving as prime contractor. The European Commission owns and manages the Copernicus programme, while EUMETSAT is scheduled to operate Sentinel-3C after completion of in-orbit testing.

Sentinel-3C was launched on 15 September 2026 at 03:21 CET from Europe's Spaceport in Kourou, French Guiana, aboard an Avio-operated Vega C rocket. It was launched together with ESA's FLEX Earth-observation satellite and entered orbit successfully.

Development and launch

Sentinel-3C was developed to maintain continuity of the Sentinel-3 observation programme alongside Sentinel-3A and Sentinel-3B. The mission supports long-term monitoring of environmental conditions and provides data for climate monitoring, environmental management, weather forecasting, agriculture, water management and marine applications.

Before launch, the European Commission stated that mission VV30 would place Sentinel-3C into a Sun-synchronous orbit at approximately 820 km altitude. The satellite had a mass of approximately 1,143 kg. The planned mission and development partnership were described by the European Commission.

The Vega C lifted off from Kourou at 01:21 UTC on 15 September 2026. Sentinel-3C and FLEX were released at an altitude of about 820 km, and both spacecraft were flying freely by 116 minutes after launch. Sentinel-3C established its first contact with Earth at 04:33 CET, confirming that the spacecraft was in good health. The successful launch was subsequently confirmed by the European Commission.

Design

Sentinel-3C carries an Earth-observation instrument suite intended to measure conditions across the oceans, land, ice and atmosphere. The mission provides systematic observations of sea surface temperature, ocean colour, sea level, land cover and other environmental indicators.

Its measurements can be used to track coastal water quality and harmful algal blooms, wildfires, droughts, vegetation health, land surface temperature, heatwaves and changes in polar ice. Sentinel-3 observations also contribute near-real-time information used for ocean and weather forecasting.

Sentinel-3C complements ESA's FLEX mission. Sentinel-3 provides broad observations of ocean, land and ecosystem conditions, while FLEX measures vegetation fluorescence. The two satellites were launched together but perform separate Earth-observation missions.

Program status

After its successful September 2026 launch and initial contact, Sentinel-3C entered a commissioning and calibration phase. Its instruments and spacecraft systems are to undergo several months of testing before the satellite becomes fully operational.

Once commissioning is complete, Sentinel-3C is intended to work alongside the other Sentinel-3 spacecraft and maintain the long-term availability of Copernicus Earth-observation data.

Operators

• European Commission: Owns and manages Sentinel-3C as part of the European Union's Copernicus Earth-observation programme.
• EUMETSAT: Scheduled to operate Sentinel-3C and deliver its data and services after completion of in-orbit testing.

Specifications (Copernicus Sentinel-3C)

General characteristics

• Type: Earth-observation satellite
• Mass: Approximately 1,143 kg
• Developer: European Space Agency, on behalf of the European Commission
• Prime contractor: Thales Alenia Space
• Programme: European Union Copernicus Earth-observation programme

Orbit and mission

• Orbit: Sun-synchronous orbit
• Orbital altitude: Approximately 820 km
• Observation areas: Oceans, land, ice and atmosphere
• Measurements: Sea surface temperature, ocean colour, sea level, land cover and other environmental indicators

Launch

• Launch date: 15 September 2026
• Launch vehicle: Vega C
• Mission: VV30
• Launch site: Europe's Spaceport, Kourou, French Guiana
• Co-passenger: FLEX Earth-observation satellite