CAPE CANAVERAL, Fla. — A NASA spacecraft rocketed away Monday on a quest to explore Jupiter’s tantalizing moon Europa and reveal whether its vast hidden ocean might hold the keys to life.

It will take Europa Clipper 5 1/2 years to reach Jupiter, where it will slip into orbit around the giant gas planet and sneak close to Europa during dozens of radiation-drenched flybys.

Scientists are almost certain that a deep, global ocean exists beneath Europa’s icy crust. And where there is water, there could be life, making the moon one of the most promising places out there to hunt for it.

Europa Clipper won’t look for life; it has no life detectors. Instead, the spacecraft will zero in on the ingredients necessary to sustain life, searching for organic compounds and other clues as it peers beneath the ice for suitable conditions.

SpaceX started Clipper on its 1.8 billion-mile journey, launching the spacecraft on a Falcon Heavy rocket from Kennedy Space Center in Florida. An hour later, the spacecraft separated from the upper stage, floated off and called home.

“The science on this is really captivating,” NASA Associate Administrator Jim Free said from the launch site. Scientists are still learning about the depths of our own ocean, “and here we are looking that far out.”

The $5.2 billion mission almost got derailed by transistors.

NASA didn’t learn until spring that Clipper’s transistors might be more vulnerable to Jupiter’s intense radiation field than anticipated. Clipper will endure the equivalent of several million chest X-rays during each of the 49 Europa flybys.

The space agency spent months reviewing everything before concluding in September that the Jupiter mission could proceed as planned. Then Hurricane Milton delayed the launch.

Clipper, about the size of a basketball court with its solar wings unfurled, will swing past Mars and then Earth on its way to Jupiter for gravity assists. The nearly 13,000-pound probe should reach the solar system’s biggest planet in 2030.

Clipper will circle Jupiter every 21 days. One of those days will bring it close to Europa, among 95 known moons at Jupiter and close to our own moon in size.

The spacecraft will skim as low as 16 miles above Europa — much closer than the few previous visitors. Onboard radar will attempt to penetrate the moon’s ice sheet, believed to be at least 10 to 15 miles thick.

The ocean below could be 80 miles or more deep.

The spacecraft holds nine instruments, with its sensitive electronics stored in a vault with dense zinc and aluminum walls for protection against radiation.

Exploration will last until 2034.

“Ocean worlds like Europa are not only unique because they might be habitable, but they might be habitable today,” NASA team member Gina DiBraccio said on the eve of launch.

With an underground ocean and geysers, Saturn’s moon Enceladus is another top candidate.