A satellite aimed at measuring global sea surface heights was launched.

VANDENBERG AIR FORCE BASE, Calif. — A U.S.-European satellite designed to extend a decades-long measurement of global sea surface heights was launched into Earth orbit from California on Saturday.

A SpaceX Falcon 9 rocket carrying the satellite blasted off from Vandenberg Air Force Base at 9:17 a.m. and arced southward over the Pacific Ocean. The Falcon’s first stage flew back to the launch site and landed for reuse.

The Sentinel-6 Michael Freilich satellite was released from the second stage about an hour later. It then deployed its solar panels and made first contact with controllers.

The satellite was named for a former NASA official who had a key role in developing space-based oceanography. Its main instrument is an extremely accurate radar altimeter that will bounce energy off the sea surface as it sweeps over Earth’s oceans. An identical twin, Sentinel-6B, will be launched in 2025.

Space-based sea level measurements have been uninterrupted since the 1992 launch of the U.S.French satellite TOPEX-Poseidon, which was followed by a series of satellites including the current Jason-3.

Sea surface heights are affected by heating and cooling of water, allowing scientists to use the altimeter data to detect such weather-influencing conditions as the warm El Nino and the cool La Nina.

The measurements are also important for understanding overall sea level rise due to global warming.

“Our Earth is a system of intricately connected dynamics between land, ocean, ice, atmosphere and also of course our human communities, and that system is changing,” said Karen St. Germain, NASA’s Earth Science Division director.

The new satellite is expected to have unprecedented accuracy.