The Copernicus Sentinel-3C satellite has transmitted its first images and scientific measurements back to Earth, just two weeks after launching into orbit, the European Space Agency confirmed. The spacecraft is now operational and collecting data on ocean temperatures, sea surface height, and land vegetation across the planet.
Sentinel-3C joins two identical satellites already in orbit — Sentinel-3A and Sentinel-3B — to complete a three-satellite constellation that provides near-global coverage of Earth's surface every two days. The mission is part of the European Union's Copernicus program, which delivers free environmental data to governments, scientists, and businesses worldwide.
The satellite carries instruments designed to measure sea surface temperature with precision better than 0.3 degrees Celsius, track ocean color to monitor phytoplankton blooms, and map land surface temperature and vegetation health. These measurements feed into weather forecasting models, climate research, and fisheries management.
Sentinel-3C launched aboard a Vega-C rocket from Europe's Spaceport in Kourou, French Guiana. The European Space Agency said the satellite will undergo several months of commissioning before entering full operational service, replacing Sentinel-3A, which has exceeded its design life since launching in 2016.
The Sentinel-3 mission has recorded a steady rise in global sea surface temperatures over the past decade, with 2023 and 2024 ranking as the warmest years on record for ocean heat content, according to data from the National Oceanic and Atmospheric Administration. The satellite constellation provides the continuous measurements researchers rely on to track these trends.
The Copernicus program, which is coordinated by the European Commission in partnership with ESA, operates six families of Sentinel satellites monitoring different aspects of the Earth system — from atmospheric composition to land use changes. The data is distributed freely to users in more than 180 countries.
Sentinel-3C carries a radar altimeter that measures sea level to within a few centimeters, a key metric for tracking global sea level rise, which currently runs at about 3.4 millimeters per year, according to NASA satellite records. The instrument also measures wave height and wind speed over the ocean surface.
ESA did not disclose a specific timeline for when Sentinel-3C data will become publicly available through the Copernicus Open Access Hub, but the agency said commissioning is proceeding on schedule.
