ESA’s ‘JUICE’ spacecraft takes off on epic voyage to Jupiter

An Ariane 5 rocket blasts off from Kourou, French Guiana, carrying the European Space Agency’s Jupiter Icy Moons Explorer spacecraft. Image: ESA

The European Space Agency’s Jupiter Icy Moons Explorer spacecraft – JUICE – is finally on its way to the solar system’s largest planet, carrying a suite of state-of-the-art instruments to probe frozen moons where sub-surface oceans may host habitable environments.

Perched atop an Ariane 5 rocket, JUICE began its eight-year trip to Jupiter at 1214 UTC on 14 April, one day late because of stormy weather at the Kourou, French Guiana, spaceport. But it was clear sailing the second time around, and the spacecraft was released to fly on its own about a half hour after launch.

After a tense few minutes waiting for the spacecraft to contact ground controllers, confirming it was in good health, JUICE’s two enormous 85-square metre (615-square-foot) solar arrays unfolded and locked in place, providing the power needed to recharge the probes batteries and power its myriad systems.

“We have a mission, we’re flying to Jupiter!” said Andrea Accomazzo, spacecraft operations manager. “We go there fully loaded with questions. Europe is getting there, Jupiter, get ready for it!”

But it will not be quick.

An artist’s impression of the JUICE spacecraft flying through the Jupiter system, with repeated flybys of Europa, Callisto and Ganymede, frozen worlds that may host habitable seas beneath their icy crusts. Image: ESA

Despite the 2.9 million pounds of thrust delivered by the Ariane 5 rocket at liftoff, the 6.5-ton JUICE could not be fired directly to Jupiter. Instead, the craft will utilise the gravity of Earth and Venus to pump up its velocity, flying back by Earth in August 2024, then once past Venus in August 2025 and twice more by Earth in 2026 and 2029.

If all goes well, the spacecraft will finally reach Jupiter in July 2031 to carry out exhaustive studies of the planet’s atmosphere, magnetic field and radiation environment while making repeated flybys of its three major ice moons — Europa, Callisto and Ganymede.

A major objective is to look for signs of habitability in sub-surface oceans warmed by tidal heating in Jupiter’s crushing gravity. JUICE will spend the final months of its mission in orbit around Ganymede, eventually crashing to the surface when it finally runs out of propellant.

JUICE will end its mission orbiting Ganymede, the largest moon in the solar system and the only one with a magnetic field. (Image: NASA)

“We’ll explore Jupiter and its icy moons, which are Europa, Ganymede and Callisto with a particular focus on Ganymede, the only moon with magnetic field and the biggest moon of the solar system,” said European Space Agency project scientist Olivier Witasse. “The main goal is to understand whether there are habitable environments among those icy moons around a giant planet like Jupiter.

“And to understand this question of habitability, we need to explore the Jupiter system globally,” he said. “So (JUICE will) study Jupiter, its atmosphere, its weather, its strong, rotating magnetic field, the volcanic moon Io, the other moons in the system and how all these bodies are connected to each other.”