VANDENBERG AIR FORCE BASE, CALIF. An American-European satellite designed to extend a decades-long measurement of global sea levels was launched into Earth’s orbit from California on Saturday.
A SpaceX Falcon 9 rocket carrying the satellite exploded from Vandenberg Air Force Base at 9:17 a.m. and arced south across the Pacific Ocean. Falcon’s first leg 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 drove out its solar panels and made first contact with control units.
The satellite’s main instrument is named after a former NASA official who played a key role in the development of space-based oceanography and is an extremely accurate radar altimeter that will bounce energy from the sea surface as it sweeps across Earth’s oceans. An identical twin, Sentinel-6B, will be launched in 2025 to ensure the continuity of the records.
Space-based sea level measurements have been interrupted since the 1992 launch of the US-French satellite TOPEX-Poseidon, which was followed by a series of satellites including the current Jason-3.
Sea levels are affected by water heating and cooling, enabling researchers to use altimeter data to detect weather conditions such as the warm El Nino and the cool La Nina.
The measurements are also important for understanding the total sea level rise due to global warming, which scientists warn is a risk to the world’s coastlines and billions of people.
“Our earth is a system with intricately linked dynamics between land, sea, ice, atmosphere and, of course, our human societies, and that system is changing,” said Karen St. Germain, NASA’s Head of the Earth Science Division, in a pre-launch. briefing Friday.
“Because 70% of the earth’s surface is ocean, oceans play a huge role in how the whole system changes,” she said.
The new satellite is expected to have unmatched accuracy.
“This is an extremely important parameter for climate monitoring,” Josef Aschbacher, the European Space Agency’s head of Earth observation, told the Associated Press this week.
“We know sea levels are rising,” Aschbacher said. The big question is, how much, how fast.
Other instruments on board will measure how radio signals pass through the atmosphere and provide atmospheric temperature and humidity data that can help improve global weather forecasts.
Europe and the United States are splitting $ 1.1 billion (900 million euros) for the mission, which includes the twin satellite.
Associated Press journalist Frank Jordans contributed to this report from Berlin.