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 expected to deploy its solar panels and later make first contact with controllers.
Named for a former NASA official who had a key role in developing space-based oceanography, the satellite's 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 to ensure continuity of the record.
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 scientist 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 that scientists warn is a risk to the world's coastlines and billions of people.
The new satellite is expected to have unprecedented accuracy.
Earlier this month SpaceX launched four astronauts to the International Space Station in the first full-fledged taxi flight for NASA by a private company. Here are photos from that launch:
This undated photo made available by SpaceX in September 2020 shows, from left, NASA astronauts Shannon Walker, Victor Glover, commander Mike Hopkins and Japan Aerospace Exploration Agency astronaut Soichi Noguchi inside SpaceX's Crew Dragon spacecraft. The four are scheduled to be SpaceX’s second crew launch in mid-November 2020. (SpaceX via AP)
FILE - In this Thursday, Sept. 24, 2020, photo released by SpaceX, NASA astronauts, from left, mission specialist Shannon Walker, pilot Victor Glover, Crew Dragon commander Michael Hopkins and Japan Aerospace Exploration Agency mission specialist Soichi Noguchi pose for a photo during crew equipment interface testing at SpaceX headquarters in Hawthorne, Calif. The four are scheduled to be SpaceX’s second crew launch in mid-November 2020. (SpaceX via AP, File)
A Falcon 9 SpaceX rocket with the Crew Dragon capsule is seen during a time exposure as it lifts off from pad 39A at the Kennedy Space Center in Cape Canaveral, Fla., Sunday, Nov. 15, 2020. Four astronauts are beginning a mission to the International Space Station. (AP Photo/John Raoux)
A SpaceX Falcon9 rocket, with the Crew Dragon capsule attached, lift's off from Kennedy Space Center's Launch Complex 39-A Sunday Nov. 15, 2020, in Cape Canaveral, Fla. Four astronauts are beginning a mission to the international Space Station. (AP Photo/Chris O'Meara)
A SpaceX Falcon9 rocket, with the Crew Dragon capsule attached, flies downrange from Kennedy Space Center's Launch Complex 39-A Sunday Nov. 15, 2020, in Cape Canaveral, Fla. Four astronauts are beginning a mission to the international Space Station. (AP Photo/Chris O'Meara)
A SpaceX Falcon9 rocket, with the Crew Dragon capsule attached, lift's off from Kennedy Space Center's Launch Complex 39-A Sunday Nov. 15, 2020, in Cape Canaveral, Fla. Four astronauts are beginning a mission to the international Space Station. (AP Photo/Chris O'Meara)
NASA astronauts Shannon Walker, left, and Michael Hopkins smile at family members as they leave the Operations and Checkout Building on their way to launch pad 39A for the SpaceX Crew-1 mission to the International Space Station at the Kennedy Space Center in Cape Canaveral, Fla., Sunday, Nov. 15, 2020. (Photo/John Raoux)
NASA astronauts, Victor Glover, left, and Japan Aerospace Exploration Agency astronaut Soichi Noguchi wave to family and friends as they leave the Operations and Checkout Building on their way to launch pad 39A for the SpaceX Crew-1 mission to the International Space Station at the Kennedy Space Center in Cape Canaveral, Fla., Sunday, Nov. 15, 2020. (Photo/John Raoux)
A NASA helicopter is seen flying past a SpaceX Falcon 9 rocket with the company's Crew Dragon spacecraft onboard on the launch pad at Launch Complex 39A as the countdown progresses for the launch of the Crew-1 mission, Sunday, Nov. 15, 2020, at NASA's Kennedy Space Center in Florida. (Joel Kowsky/NASA via AP)
A SpaceX Falcon9 rocket, with the Crew Dragon capsule attached, sits at the Kennedy Space Center's Launch Complex 39-A for an evening launch, Sunday, Nov. 15, 2020, in Cape Canaveral, Fla. The crew is headed to the International Space Station. (AP Photo/Chris O'Meara)
Fuel is purged from the SpaceX Falcon9 rocket, with the Crew Dragon capsule attached, as it sits at the Kennedy Space Center's Launch Complex 39-A for an evening launch Sunday Nov. 15, 2020, in Cape Canaveral Fla. The crew is headed to the International Space Station. (AP Photo/Chris O'Meara)
A SpaceX Falcon9 rocket, with the Crew Dragon capsule attached, lift's off from Kennedy Space Center's Launch Complex 39-A Sunday Nov. 15, 2020, in Cape Canaveral, Fla. Four astronauts are beginning a mission to the international Space Station. (AP Photo/John Raoux)
A SpaceX Falcon9 rocket, with the Crew Dragon capsule attached, lift's off from Kennedy Space Center's Launch Complex 39-A Sunday Nov. 15, 2020, in Cape Canaveral, Fla. Four astronauts are beginning a mission to the international Space Station. (AP Photo/Chris O'Meara)
Japan Aerospace Exploration Agency (JAXA) astronaut Soichi Noguchi, wearing a SpaceX spacesuit, is seen as he prepares to depart the Neil A. Armstrong Operations and Checkout Building with his fellow crewmates NASA astronauts Victor Glover, Mike Hopkins, and Shannon Walker for Launch Complex 39A to board the SpaceX Crew Dragon spacecraft for the Crew-1 mission launch, Sunday, Nov. 15, 2020, at NASA's Kennedy Space Center in Florida. (Joel Kowsky/NASA via AP)
NASA astronauts Victor Glover, front left, Mike Hopkins, front right, Shannon Walker, back left, and Japan Aerospace Exploration Agency (JAXA) astronaut Soichi Noguchi, back right, wearing SpaceX spacesuits, are seen as they walk out of the Neil A. Armstrong Operations and Checkout Building to depart for Launch Complex 39A to board the SpaceX Crew Dragon spacecraft for the Crew-1 mission launch, Sunday, Nov. 15, 2020, at NASA's Kennedy Space Center in Florida. (Joel Kowsky/NASA via AP)
NASA Administrator Jim Bridenstine, Gwynne Shotwell, president and chief operating officer of SpaceX, and NASA Deputy Administrator Jim Morhard wave as NASA astronauts Mike Hopkins, Victor Glover, Shannon Walker, and Japan Aerospace Exploration Agency (JAXA) astronaut Soichi Noguchi, wearing SpaceX spacesuits, wave as they prepare to depart the Neil A. Armstrong Operations and Checkout Building for Launch Complex 39A to board the SpaceX Crew Dragon spacecraft for the Crew-1 mission launch, Sunday, Nov. 15, 2020, at NASA's Kennedy Space Center in Florida. (Joel Kowsky/NASA via AP)
NASA astronauts Shannon Walker, left, Victor Glover, second from left, Mike Hopkins, second from right, and Japan Aerospace Exploration Agency (JAXA) astronaut Soichi Noguchi, right, wearing SpaceX spacesuits, wave as they walkout of the Neil A. Armstrong Operations and Checkout Building to depart for Launch Complex 39A to board the SpaceX Crew Dragon spacecraft for the Crew-1 mission launch, Sunday, Nov. 15, 2020, at NASA's Kennedy Space Center in Florida. NASA's SpaceX Crew-1 mission is the first crew rotation mission of the SpaceX Crew Dragon spacecraft and Falcon 9 rocket to the International Space Station as part of the agency's Commercial Crew Program. Hopkins, Glover, Walker, and Noguchi are scheduled to launch at 7:27 p.m. EST, from Launch Complex 39A at the Kennedy Space Center. Photo Credit: (NASA/Joel Kowsky) /// [EXTERNAL] CAPTION: ————————————————————————— NASA astronauts Shannon Walker, left, Victor Glover, second from left, Mike Hopkins, second from right, and Japan Aerospace Exploration Agency (JAXA) astronaut Soichi Noguchi, right, wearing SpaceX spacesuits, wave as they walkout of the Neil A. Armstrong Operations and Checkout Building to depart for Launch Complex 39A to board the SpaceX Crew Dragon spacecraft for the Crew-1 mission launch, Sunday, Nov. 15, 2020, at NASA's Kennedy Space Center in Florida. (Joel Kowsky/NASA via AP)
Japan Aerospace Exploration Agency astronaut Soichi Noguchi waves to family members as he leaves the Operations and Checkout Building with fellow crew members for a trip to Launch Pad 39-A and planned liftoff on a SpaceX Falcon 9 rocket with the Crew Dragon capsule on a six-month mission to the International Space Station Sunday, Nov. 15, 2020, at the Kennedy Space Center in Cape Canaveral, Fla. (AP Photo/John Raoux)
Japan Aerospace Exploration Agency astronaut Soichi Noguchi points as he rides by the Vehicle Assembly Building on the way to Launch Pad 39-A with fellow crew members for a planned liftoff on a SpaceX Falcon 9 rocket with the Crew Dragon capsule on a six-month mission to the International Space Station Sunday, Nov. 15, 2020, at the Kennedy Space Center in Cape Canaveral, Fla. (AP Photo/Chris O'Meara)
NASA astronauts, from left, Shannon Walker, Victor Glover, and Michael Hopkins and Japan Aerospace Exploration Agency astronaut Soichi Noguchi leave the Operations and Checkout Building on their way to launch pad 39A for the SpaceX Crew-1 mission to the International Space Station at the Kennedy Space Center in Cape Canaveral, Fla., Sunday, Nov. 15, 2020. (Photo/John Raoux)
NASA astronauts, from left, Shannon Walker, Victor Glover, and Michael Hopkins and Japan Aerospace Exploration Agency astronaut Soichi Noguchi leave the Operations and Checkout Building on their way to launch pad 39A for the SpaceX Crew-1 mission to the International Space Station at the Kennedy Space Center in Cape Canaveral, Fla., Sunday, Nov. 15, 2020. (Photo/John Raoux)
NASA astronaut Shannon Walker leaves the Operations and Checkout Building on her way to launch pad 39A for the SpaceX Crew-1 mission to the International Space Station at the Kennedy Space Center in Cape Canaveral, Fla., Sunday, Nov. 15, 2020. (Photo/John Raoux)
Astronauts, from left, Victor Glover, Michael Hopkins, Shannon Walker, and Japan Aerospace Exploration Agency astronaut Soichi Noguchi wave to family and friends as they leave the Operations and Checkout Building for a trip to Launch Pad 39-A and a planned liftoff on a SpaceX Falcon 9 rocket with the Crew Dragon capsule on a six-month mission to the International Space Station Sunday, Nov. 15, 2020, at the Kennedy Space Center in Cape Canaveral, Fla. (AP Photo/John Raoux)
Members of Japan Aerospace Exploration Agency astronaut Soichi Noguchi pose for a photo as the astronauts leave the Operations and Checkout Building for a trip to Launch Pad 39-A and planned liftoff on a SpaceX Falcon 9 rocket with the Crew Dragon capsule on a six-month mission to the International Space Station Sunday, Nov. 15, 2020, at the Kennedy Space Center in Cape Canaveral, Fla. (AP Photo/John Raoux)
