NASA's Europa Clipper launches aboard a SpaceX rocket

A SpaceX Falcon Heavy rocket blasted off Monday morning from Cape Canaveral, Florida, aboard a NASA probe designed to explore Jupiter's icy moon Europa and search for signs of extraterrestrial life.

With the Europa Clipper now on its 1.8 billion-mile, five-and-a-half-year journey to the solar system's largest planet, NASA has officially placed a “tremendous risk to the mission,” according to Jordan Evans, Europa Clipper project manager on the jet NASA's Propulsion Lab.

Clipper's journey will not be direct. It will be helped by gravity to slingshot around Mars early next year and then boomerang back around Earth in late 2026 before heading toward the gas giant and its icy, dynamic moon. It is scheduled to arrive in 2030 and will collect data for more than four years.

When the mission ends, Clipper will fly into one of Jupiter's rocky moons to ensure the spacecraft does not contaminate Europa.

The launch was originally scheduled for October 10, but Clipper spent that day secured in SpaceX's hangar to weather Hurricane Milton. The sky over Florida's Space Coast was clear Monday morning with just a few wispy clouds.

Scientists have been arguing for a Europa mission for decades, ever since NASA's Galileo probe discovered that the moon likely has a subsurface global ocean heated by Jupiter's gravitational forces, which compress and expand the lunar core as it pushes the gas giant orbiting at breakneck speed.

With water, an energy source in the form of heat, and possibly organic compounds, scientists say Europa could be hospitable to alien life.

As Clipper orbits Jupiter, it will fly past Europa dozens of times and use its science instruments to study the dynamics of the moon's subsurface ocean and search for organic compounds, a potential indicator of life.

The $5 billion Europa Clipper mission was designed and built by NASA's Jet Propulsion Laboratory in La Cañada Flintridge. It is the largest planetary probe ever built by the space agency.

To launch the spacecraft, SpaceX used its Falcon Heavy rocket, a variant of its Falcon 9 with an additional booster attached to each side.

While SpaceX usually tries to recover its launch vehicles, this time they dropped them into the ocean – using all of their fuel to free Clipper from Earth's gravity rather than saving some fuel for landing. The fairings that protect the spacecraft as it leaves Earth are recovered.

“The community is really fortunate to have new rockets with this heavy-lift capability,” said Matthew Shindell, curator of planetary science and research at the Smithsonian National Air and Space Museum. “If you had tried to launch a mission like this a decade ago, you wouldn’t have been able to do it.”