Juice spacecraft begins eight-year voyage to Jupiter after successful launch

An Ariane-5 rocket has launched Europe’s €1.6bn Juice spacecraft on an eight-year voyage to Jupiter and its icy moons, which it will investigate for signs that liquid oceans beneath their frozen surfaces might support life.

The successful launch was greeted with jubilation by scientists, astronauts and officials gathered in the control room at the European Spaceport in French Guiana on Friday. Teams led by the European Space Agency had worked for months testing for flaws and potential problems. The launch was postponed from Thursday because of bad weather.

“What a great satellite, what a great mission, congratulations to everybody involved,” said Bruno Texeira de Sousa, an ESA operations manager. “We have a fantastic mission ongoing.” 

Nearly an hour after lift-off the first signals were received from the spacecraft. They were captured by antennas at the New Norcia ground station in Western Australia. A second key milestone was reached when Juice’s solar rays were deployed, enabling the satellite to produce its own electricity.

ESA’s director-general Josef Aschbacher added: “This is an international partnership, but it’s also a moment of pride for Europe . . . I’m just so relieved.”

Juice — short for Jupiter Icy Moons Explorer — is the most complex planetary space mission ever attempted. Although Juice will provide a wealth of information about the atmosphere and magnetic environment of Jupiter, most public attention will focus on what it discovers about what lies beneath the moons’ icy surfaces.

Michele Dougherty, head of physics at Imperial College London, helped to develop a magnetometer which will be used to measure electrical currents in the underground oceans of Jupiter’s moons.

“We’re looking for the ingredients for life — liquid water, a heat source and organic material,” said Dougherty. “Once we confirm that is there, then we’ll be able to essentially say that the moons of Jupiter are a place where life could form.”

Even the most powerful rockets available could not give the six-tonne spacecraft enough energy to head straight to Jupiter. So instead its 6.6bn-kilometre route involves four “slingshot” gravity assists around Earth and Venus — the last one in 2029 — before reaching Jupiter, the solar system’s biggest planet, in 2031.

Juice will then orbit Jupiter, fly past the Europa and Callisto moons and then orbit a third, Ganymede, enabling its 10 scientific instruments to examine the complex physical and chemical environment of the Jovian system. The mission is due to end with Juice crashing into Ganymede in late 2035, unless discoveries show that this might risk unacceptable contamination of the moon’s surface.

“Juice provides a means of probing inside potentially habitable ocean worlds of our solar system for the first time, down into the deep, dark, hidden oceans that might be the most suitable abodes for life beyond Earth,” said Leigh Fletcher, professor of planetary science at Leicester university in the UK who has been involved in planning the mission since 2008.

“If Juice can reveal that these distant icy worlds provide genuinely habitable environments, then it has profound implications for the continued search for life [elsewhere in the universe],” he said.

British astronaut Tim Peake, who is not directly involved in Juice, said: “This is such an exciting mission, with the power to inspire the next generation of scientists and explorers. What could be more inspirational than the search for extraterrestrial life?”

Dougherty highlighted the need for patience as the spacecraft searches for signs of life on Jupiter’s moons. “I first started working on this back in 2007 . . . in some ways we’re halfway through the mission, because by the time we get there and we take in all the data it will probably [take] another 15 years,” she said.