SpaceX Falcon Heavy rocket launches NASA's Europa Clipper probe to explore icy Jupiter ocean moon (video)

Europa Clipper has set sail at long last.

NASA's Europa Clipper probe launched today (Oct. 14) atop a SpaceX Falcon Heavy rocket from NASA's Kennedy Space Center (KSC) in Florida, kicking off a highly anticipated astrobiology mission to the Jupiter ocean moon Europa.

Liftoff, from KSC's Pad 39A, occurred at 12:06 p.m. EDT (1606 GMT), when the powerful rocket's 27 first-stage Merlin engines roared to life and sent Clipper skyward.

"Liftoff of Falcon Heavy with Europa Clipper, unveiling the mysteries of an enormous ocean lurking beneath the icy crust of Jupiter's moon Europa," NASA launch commentator Derrol Nail said as the powerful rocket rose off the pad today.

The engines on the Falcon Heavy’s two side boosters cut off approximately three minutes into flight, detaching from the rocket's central core, which continued onward another minute.

Related: Facts about SpaceX's Falcon Heavy rocket

Separation of the second stage from the core booster occurred about four minutes after launch. Europa Clipper deployed on an interplanetary trajectory 58 minutes after that milestone, just as planned. And, a few minutes later, the team established communications with the probe, eliciting a round of cheers and applause in mission control. 

Today's launch occurred a few days later than originally planned, thanks to Mother Nature. NASA and SpaceX originally targeted Thursday (Oct. 10) for the liftoff but pushed things back to wait out Hurricane Milton, which slammed into Florida's Gulf Coast on Wednesday evening (Oct. 9).

NASA closed KSC to batten down against the storm. As part of these preparations, Europa Clipper was secured inside a SpaceX hangar near Pad 39A.

A landmark Heavy launch

Today's launch was the 11th overall for the Falcon Heavy, and its second interplanetary mission. It was also the first Falcon Heavy launch to require the full expenditure of the vehicle's three first-stage boosters. 

Normally, the first-stage boosters for Spacex's Falcon Heavy and Falcon 9 rockets reserve enough fuel to perform landing burns for recovery and reuse on future launches. 

NASA's Psyche asteroid probe — the first interplanetary spacecraft to fly atop a Falcon Heavy — launched almost exactly one year ago, on Oct. 13, 2023, and required full use of the rocket’s central core. But the two side boosters came back safely that day, landing downrange of Pad 39A. Europa Clipper, on the other hand, needed all the power Falcon Heavy could manage in order to send it on its way toward the Jupiter system.

A long road to the launch pad

In late 2015, Congress directed NASA to launch Europa Clipper using the Space Launch System (SLS), NASA’s massive moon rocket.

The SLS was still in development at the time, and would be for a number of years to come. Delays with the powerful rocket, and the need to dedicate at least the first three SLS vehicles to launches for NASA's Artemis moon program, pushed Europa Clipper’s liftoff date into limbo. (SLS debuted in late 2022, successfully sending the uncrewed Artemis 1 mission to the moon.)

The 2021 U.S. House of Representatives budget proposal instructed NASA to launch Europa Clipper by 2025, and to do so on an SLS "if available." Those two crucial words put the probe on a path toward a commercial launch vehicle, which turned out to be a Falcon Heavy.

The switch did not come without some tradeoffs, however. The massive power of the SLS — the brawniest rocket ever to fly an operational mission — would have flung Europa Clipper directly to the Jupiter system in less than three years. 

The trip will now take about twice that long, even though Falcon Heavy was in fully expendable mode. Europa Clipper will have to perform a Mars flyby (in February 2025) and an Earth flyby (in December 2026), in order to pick up enough velocity to reach its destination in April 2030. 

Rocket issues weren’t the only hiccups on Europa Clipper's path to the launch pad. For example, rising costs on the $5 billion spacecraft led NASA to cancel development of one of the probe’s scientific instruments — the Interior Characterization of Europa Using Magnetometry (ICEMAG), a magnetometer designed to measure Europa’s magnetic field. 

And, in May 2024, NASA discovered that transistors similar to those used aboard Europa Clipper, which are responsible for regulating electricity on the probe, "were failing at lower radiation doses than expected." The revelation prompted NASA to conduct further tests with the hardware, ultimately concluding in late August that "the transistors can support the baseline mission" to the radiation-rich environment around Jupiter.

Related: NASA's Europa Clipper on track for October launch to Jupiter's icy moon despite radiation worries

An ambitious mission to an intriguing moon

Europa Clipper is one of NASA’s most exciting and ambitious missions ever. Take the probe itself: It's the biggest spacecraft the agency has ever built for a planetary mission. It weighed about 13,000 pounds (6,000 kilograms) at launch and, with its solar panels extended, will measure about 100 feet (30 meters) long — bigger than a basketball court. 

Then there's the probe's target. Europa is one of Jupiter’s four Galilean moons. It's covered in a frozen outer crust under which scientists think a vast ocean of salty liquid water sloshes, and is widely considered one of the solar system's best bets to harbor alien life.

In addition, studies early as 2012 began to observe potential water plumes emanating from Europa's surface. Some researchers theorize that these plumes, and the vents from which they spout, may contain evidence of life beneath the moon’s icy crust.

NASA scientists are quick to clarify that Europa Clipper won’t be looking for life on Europa, but only for the potential for the environment beneath its surface to support life. 

"If there is life on Europa in this habitable environment that we're exploring, it will be underneath the ocean, so we wouldn't be able to see it," Bonnie Buratti, Europa Clipper deputy project scientist at NASA’s Jet Propulsion Laboratory in Southern California, said during a press briefing in September.

"We're looking for chemicals on the surface, organic chemicals that are the precursors to life. There are dream things we could observe," Buratti said, "like DNA or RNA, but we don't expect to see those. So, [the mission] really is just looking for a habitable environment and evidence for the ingredients of life, not life itself." 

Clipper will also characterize Europa's ice shell in detail. This work could identify good spots at which a life-hunting lander — a future mission that Congress has ordered NASA to develop — could touch down and operate.

Europa Clipper will collect data using a suite of nine science instruments, including visible-light and thermal cameras, several spectrometers and gear that will characterize Europa's magnetic environment. Together, this hardware will help mission scientists address three main objectives, as NASA's Europa Clipper page states:

• Determine the thickness of Europa’s icy shell, and understand how Europa’s ocean interacts with the surface;
• Investigate the composition of Europa’s ocean to determine if it has the ingredients to permit and sustain life;
• Study how Europa’s surface features formed and locate any signs of recent activity, such as sliding crust plates or plumes that are venting water into space.

Clipper is also carrying some culture from Earth to the Jupiter system — "In Praise of Mystery: A Poem for Europa," written by U.S. Poet Laureate Ada Limón. The poem is engraved, in her own handwriting, on a metal plate that serves as a seal for the probe's "vault," which helps protect its instruments and key electronics against radiation.

The poem is part of NASA's "Message in a Bottle" outreach campaign, which also features a dime-sized chip engraved with the names of 2.6 million people who wanted a piece of themselves to fly to Europa.

Dozens of Europa flybys

If all goes according to plan, Europa Clipper will enter orbit around Jupiter in April 2030. When it gets there, the spacecraft will perform an insertion burn lasting six to eight hours and expelling 50% to 60% of the probe’s 6,000 pounds (2,722 kilograms) of propellant. 

The burn will put the probe into an elliptical orbit around the gas giant. It will then begin a lengthy series of maneuvers to align its trajectory so that the probe can study Europa up close over 45 or so flybys. (Clipper will remain in orbit around Jupiter; orbiting Europa would have been too risky for the mission, given the moon's intense radiation environment.)

The first Europa flyby won’t occur until spring 2031. NASA will use this first pass to make further corrections to Clipper’s course in preparation for the probe’s first science campaign. Over dozens of flybys beginning in May 2031, Europa Clipper will focus its sensor array on the moon’s anti-Jovian side (the hemisphere facing away from Jupiter), flying as close as 16 miles (25 kilometers) above the surface. A second science campaign will begin two years later, in May, 2033, on Europa’s Jupiter-facing hemisphere.

Europa Clipper’s scheduled end of mission is set for September 2034, when NASA plans to crash the spacecraft into Ganymede, another of Jupiter’s Galilean moons. This disposal strategy was chosen because Ganymede is viewed as a relatively poor bet to host life, and mission team members want to make sure they don't contaminate the potentially life-hosting Europa with microbes from Earth.

Editor's note: This story was updated at 1:15 p.m. ET on Oct. 14, with news that Europa Clipper deployed successfully and established communications with mission control.