Europe's Juice spacecraft launches to Jupiter's moons

The spacecraft successfully launched from the Kourou spaceport in French Guiana at 09:14 local time (12:14 GMT/UTC) on Friday.

Juice, or Jupiter Icy Moons Explorer, is the European Space Agency's (ESA) biggest planetary mission to date.

Juice got in contact with home just under an hour after lift-off, and the so-called "acquisition of signal" was announced in ESA's main control room in Darmstadt, Germany.

"Wow! These are the words that every spacecraft operations engineer wants to hear," said Bruno Sousa, ESA's Juice deputy flight director, on hearing that the spacecraft was transmitting a signal after launch. 

The spacecraft will explore Jupiter's complex environment and shed light on whether life could exist on three of its moons.

The lift-off was postponed from Thursday to Friday after a threat of lightning at the launch site.

Stephane Israel, the CEO of Arianespace, the company in charge of the Ariane 5 rocket carrying Juice out of Earth's atmosphere, described the delayed lift-off as an "absolutely perfect launch." 

What's next after launch?

Once Juice separates from its Ariane 5 rocket just under half an hour after launch, ESA will assume control of the spacecraft after ground stations pick up the mission’s first words.

Juice’s 85-square meter solar arrays, which stretch out to the length of a basketball court, will unfold, to collect as much energy as possible near Jupiter.

It will take up to 17 days for Juice’s antennas and probes to be deployed.

Only then will Juice begin its eight-year journey to the gas giant, which is some 628 million kilometers from Earth.

The probe will use gravitational slingshots from flying close to planets to gain momentum for its journey — Juice will do a fly-by of Earth and Venus before swinging past Earth again in 2029. Juice will arrive at its destination, Jupiter, in 2031.

Why Jupiter's moons?

More than 400 years ago astronomer Galileo Galilei spotted four moons orbiting Jupiter ― the first natural satellites discovered circling around a planet other than Earth.

Three of the four Galilean moons ― Ganymede, Callisto and Europa ― are thought to have huge oceans of liquid water beneath their icy shells. This has made Jupiter's icy moons prime candidates in the search for life beyond Earth. 

"With Juice we will explore conditions to see if life could have evolved and also to find out where to look," Hauke Hussmann from the Institute of Planetary Research in Berlin told DW.

Where exactly on Jupiter's moons find evidence of life might be most likely to be found will be a task of subsequent missions, according to Hussmann.

"Studying this gas giant planet and its moons in detail would also help our understanding of planets elsewhere in the Universe," said Professor Mark McCaughrean from ESA's senior advisors.

The first scientific results from the environment on Jupiter's moons are expected after 2031, when Juice is scheduled to arrive at Jupiter.

vh/msh (AFP, dpa)