ESA spacecraft on way to Jupiter and its icy moons

A European spacecraft rocketed away on a decade long quest to explore Jupiter and three of its icy moons that could have buried oceans.

The journey began with a perfect morning liftoff by European Space Agency’s Ariane rocket from French Guiana on the coast of South America. But there were some tense minutes later as controllers’ awaited signals from the spacecraft.

When contact finally was confirmed close to an hour into the flight, Mission Control in Germany declared “The spacecraft is alive!”

“It’s a moment of pride for Europe,” noted Josef Aschbacher, the space agency’s director general. “I’m just relieved and just so happy.”

It will take the robotic explorer, dubbed Juice, eight years to reach Jupiter, where it will scope out not only the solar system’s biggest planet but also Europa, Callisto and Ganymede. The three ice-encrusted moons are believed to harbor underground oceans, where sea life could exist.

Then in perhaps the most impressive feat of all, Juice will attempt to go into orbit around Ganymede: No spacecraft has ever orbited a moon other than our own.

With so many moons – at last count 95 – astronomers consider Jupiter a mini solar system of its own, with missions like Juice long overdue.

“We are not going to detect life with Juice,” stressed project scientist, Olivier Witasse.

But learning more about the moons and their potential seas will bring scientists closer to answering the is-there-life-elsewhere question. “That will be really the most interesting aspect of the mission,” Witasse said.

Juice is taking a long, roundabout route to Jupiter, covering 4 billion miles.

It will swoop within 125 miles of Callisto and 250 miles of Europa and Ganymede, completing 35 flybys while circling Jupiter. Then it will hit the brakes to orbit Ganymede, the primary target of the 1.6 billion-euro mission (nearly $1.8 billion).

Ganymede is not only the solar system’s largest moon – it surpasses Mercury – but has its own magnetic field with dazzling auroras at the poles.

Even more enticing, it’s thought to have an underground ocean holding more water than Earth. Ditto for Europa and its reported geysers, and heavily cratered Callisto, a potential destination for humans given its distance from Jupiter’s debilitating radiation belts, according to Carnegie Institution’s Scott Sheppard, who’s not involved with the Juice mission.

The spacecraft, about the size of a small bus, won’t reach Jupiter until 2031, relying on gravity-assist flybys of Earth and our moon, as well as Venus.

Juice – short for Jupiter Icy Moons Explorer – will spend three years buzzing Callisto, Europa and Ganymede. The spacecraft will attempt to enter orbit around Ganymede in late 2034, circling the moon for nearly a year before flight controllers send it crashing down in 2035, later if enough fuel remains.

Europa is especially attractive to scientists hunting for signs of life beyond Earth. Juice will keep its Europa encounters to a minimum, however, because of the intense radiation there so close to Jupiter.

Juice’s sensitive electronics are encased in lead to protect against radiation. The 14,000-pound (6,350-kilogram) spacecraft also is wrapped with thermal blankets – temperatures near Jupiter hover around minus 380 degrees Fahrenheit (minus 230 degrees Celsius). And its solar panels stretch 88 feet (27 meters) tip to tip to soak in as much sunlight that far from the sun.

Late next year, NASA will send an even more heavily shielded spacecraft to Jupiter, the long-awaited Europa Clipper, which will beat Juice to Jupiter by more than a year because it will launch on SpaceX’s mightier rocket. The two spacecraft will team up to study Europa like never before.

NASA has long dominated exploration at Jupiter, beginning with flybys in the 1970s by the twin Pioneers and then Voyagers. Only one spacecraft remains humming at Jupiter: NASA’s Juno, which just logged its 50th orbit since 2016.