The Sentinel-3C satellite, launched on September 15, 2026, from the Guiana Space Center using a Vega-C rocket developed by Avio, joins a series of Earth-observing satellites that began with Sentinel-3A in 2016. As the third satellite in a program started in 2007, Sentinel-3C monitors oceans, land, ice, and the atmosphere, providing crucial data for climate research, weather prediction, environmental protection, and disaster response. It is especially important for tracking ocean conditions, including rising sea temperatures and the impact of major weather patterns like El Niño. Scientists predict that the next six months will bring frequent rain and high temperatures, with weather patterns shaped by complex atmospheric changes. Sentinel-3C is a major addition to the Copernicus program, a European Union initiative focused on Earth observation. Its instruments monitor land and vegetation, water quality, surface temperatures, and sea level, helping track environmental changes, natural hazards, and ecosystem health. The satellite’s data supports global efforts to understand climate change and its effects on the planet. Milen Tahtadjiev, head of the Copernicus Sentinel-3 mission at Eumetsat, and Estelle Obligis, head of marine applications at Eumetsat, have emphasized the importance of maintaining continuous data collection. Sentinel-3C is designed to replace Sentinel-3A, which launched in 2016 and is still fully operational, ensuring that data remains consistent over time. Sentinel-3 satellites have made significant scientific contributions, including tracking global sea level rise and climate warming. Using radar altimetry and surface temperature measurements, they have documented a steady increase in sea levels and provided insights into ocean and climate changes. The satellites have also improved understanding of marine ecosystems through their ocean color imaging capabilities. Over three decades of satellite altimetry, including Sentinel-3, have shown that sea levels are rising at an accelerating rate—about 4 mm per year in the last decade compared to 3 mm per year previously. Sentinel-3’s unique combination of instruments has enabled discoveries that would not have been possible with separate missions, such as tracking forest fires with high precision. The data from Sentinel-3 has also revealed new insights into climate phenomena, such as the recent El Niño event. New tools like the "Fire Radiative Power" developed from Sentinel-3 data have become essential for monitoring forest fires. Sentinel-3 data has helped refine and confirm climate trends observed in earlier missions, especially in polar regions. It has also supported maritime safety, air quality monitoring, and disaster response. For example, data from Sentinel-3 has been used to monitor icebergs in Nordic countries and detect fires, such as those in Greece in August 2026. Looking ahead, the next generation of Sentinel satellites, Sentinel-3NGO (S3NGO), is being designed to improve on the current models. The goal is to maintain data continuity while enhancing measurement accuracy and resolution. A tandem flight phase with existing Sentinel-3 satellites will ensure that data remains consistent over time. The "super-instrument" concept, combining advanced sensors for ocean and land monitoring, aims to improve the detection and tracking of pollution. These advancements will help scientists better understand ocean circulation, the planet’s energy balance, and the effects of climate change on ice and sea levels.