Launched in November 2020, Sentinel-6 Michael Freilich was the first of two identical satellites designed to measure the height of the ocean — a key component to understanding Earth’s changing seas. Its twin, Sentinel-6B, is scheduled to launch in late 2025. The staggered launches will help to ensure the continuation of a decades-long record of sea level observations out to 2030. The satellites are part of the Sentinel-6/Jason-CS (Continuity of Service) mission, an international effort designed to measure sea levels down to roughly an inch for about 90% of the world’s ocean.
