• Because Europa conceals a vast ocean beneath its icy surface, scientists believe the celestial body presents one of the best opportunities to understand how life could exist beyond Earth.
• However, Milton, which had strengthened Monday to a Category 4 storm, is putting a pause on the planned Thursday launch.

A brewing hurricane is forcing NASA to once again scrub a rocket launch, this time for its highly anticipated Europa Clipper mission.

The uncrewed orbiter had been on track to takeoff Thursday on a SpaceX rocket in Florida, beginning its six-year cosmic journey to the Jupiter moon Europa to search for signs of life-supporting conditions.

But that was before Hurricane Milton began roaring toward the state's already battered western coast. The life-threatening storm is also expected to bring heavy rain and high winds to Florida's east coast, where the launch site at the Kennedy Space Center is located.

Ahead of landfall, NASA and SpaceX made the call to delay the Clipper launch as teams secured the spacecraft in a hangar at Launch Complex 39A, NASA said. The move comes just little more than a week after Hurricane Helene forced multiple delays of the Crew-9 mission, which sent a pair of astronauts to the International Space Station on a vehicle that will eventually bring the Boeing Starliner crew back to Earth.

“The safety of launch team personnel is our highest priority, and all precautions will be taken to protect the Europa Clipper spacecraft,” Tim Dunn, senior launch director at NASA’s Launch Services Program, said in a statement.

Hurricane Milton forces NASA to delay Clipper launch

Launch teams had prepared NASA’s Europa Clipper spacecraft on Friday to be integrated with the SpaceX Falcon Heavy rocket amid final launch preparations ahead of its mission to Jupiter’s icy moon.

The rocket was set to be rolled to the launch pad and raised to a vertical position ahead of its launch window opening Thursday before NASA delayed the mission Sunday due to Milton.

As of early Monday, Milton had strengthened from a major Category 3 to a Category 4 storm, driving sustained winds of 150 mph as it rolled across the Gulf of Mexico.

While it may weaken before the hurricane reaches the coast, Milton "is still likely to be a large and powerful hurricane at landfall in Florida," hurricane center specialist Jack Beven wrote in an advisory.

What is the Europa Clipper mission?

NASA has been planning for years to send the Europa Clipper spacecraft to Jupiter's fourth largest moon of the same name.

Because Europa conceals a vast ocean beneath its icy surface, scientists believe the celestial body presents one of the best opportunities to understand how life could exist beyond Earth. Scientists have long theorized that the icy crust above the ocean conceals evidence of organic compounds and energy sources that could potentially allow lifeforms to thrive.

With its massive solar arrays and radar antennas, the Clipper is the largest spacecraft NASA has ever developed for a planetary mission. When the uncrewed orbiter reaches the moon by 2030, it will begin the historic task of mapping and scanning above and beneath Europa's surface during nearly 50 flybys to determine whether the celestial body is indeed habitable, as scientists have long suspected.

NASA to determine new Clipper launch date

NASA officials have not yet announced a new target launch date for the Europa Clipper, though the space agency indicated that the window is open until Nov. 6.

Once Milton passes, teams plan to ensure the spaceport is safe for launch crews to return and continue preparations. The facilities at the Kennedy Space Center will also be assessed for storm damage, NASA said.

“Once we have the ‘all-clear’ followed by facility assessment and any recovery actions, we will determine the next launch opportunity for this NASA flagship mission,” Dunn said.

Contributing: John Bacon, USA TODAY

Eric Lagatta covers breaking and trending news for USA TODAY. Reach him at [email protected]