The spacecraft separated from the Ariane 5 rocket in 28 minutes. Over the next 17 days, Juice deploys its solar arrays, antennas and other instruments, followed by three months of instrument fabrication and testing.

The Jupiter IC Moons Explorer, or JUICE, mission is scheduled to lift off Thursday at 8:15 a.m. Miami time on an Ariane 5 rocket from the European Space Station Couro in French Guiana. But the Lightning postponed the release, which was moved to 8:14 a.m. Miami time on Friday.

Weather conditions often cause launch delays and postponements. Rockets must meet certain weather conditions to launch safely. The James Webb Space Telescope, which launched aboard Ariane 5 from the same location in December 2021, suffered similar delays due to bad weather around Couro.

It takes eight years for the juice to reach Jupiter, the largest planet in our solar system. During its long journey, the spacecraft will use some gravitational waves to ease the journey as it passes Earth, the Moon and Venus.

When Zeus reaches Jupiter in July 2031, the spacecraft will spend about three and a half years orbiting the gas giant and fly by its three moons, Ganymede, Callisto and Europa. At the end of the mission, Juice will focus solely on orbiting Ganymede, making it the first spacecraft to orbit a moon in the outer solar system.

An illustration depicts the juice on its way to Jupiter. Credit: European Space Agency.

Ganymede, Callisto, and Europa are ice-covered worlds that may have habitable underground oceans.

For its part, NASA’s Europa Clipper mission, which will launch in 2024, is expected to reach Jupiter in April 2030 and make about 50 flybys of Europa, coming just 25 kilometers (16 miles) above the moon’s surface.

Together, the two missions could reveal some big mysteries about Jupiter and its moons.

Close to the king of the solar system

Jupiter exploration began in the 1970s with NASA’s Pioneer and Voyager missions, followed by dedicated Jupiter missions such as the Galileo and Juno probes. Juno orbits Jupiter and has been flying by some of its moons since 2016.

The main goal of the Juno mission is to characterize the three icy moons, determine if they have oceans, identify characteristics that make Ganymede unique, and determine whether these moons are habitable. This work will use a set of 10 tools to achieve these objectives.

Planetary scientists want to know how deep the oceans are, whether they contain salt water or fresh water, and how that water interacts with each moon’s ice. Ganymede, Callisto and Europa have different surfaces. The sap function explains the function of certain moons to produce a dark or pale and streaky appearance.

Ganymede is the largest moon in the Solar System, larger than Pluto and Mercury, and has a similar magnetic field to Earth. Instruments on board can reveal the rotation, gravity, shape, interior structure and composition of Jupiter’s moons, as well as peer into its icy crust using radar.

An artist’s rendering shows the Juice mission flying over Ganymede, with Jupiter in the background. Credit: European Space Agency

Juice will analyze Jupiter and its moons, and how the radiation and magnetic environment affected their formation. Understanding Jupiter’s origin will help scientists apply their findings to gas giant-like planets.

Jupiter’s magnetic field is 20 times stronger than Earth’s and its radiation environment is harsher, affecting its moons. The JUICE mission will investigate interactions between Jupiter and its moons, including auroras, hot spots, radio emissions and waves of charged particles.

Life skills

Although all three moons are covered by thick layers of ice, the cores of each are warming, and that warming could create potential habitats for past or present life in the oceans.

Moons can look for clues to the building blocks of life, including elements like carbon, oxygen, nitrogen, iron and magnesium.

Earlier missions to Saturn, such as Galileo and Cassini, confirmed the existence of liquid water on planets and moons far from the Sun, and the possibility of subsurface water.

“I think so [la misión] JUICE confirms that our knowledge of where to look for potential habitats has changed over the past 20 years,” says Michael Dougherty, Royal Society Research Professor at Imperial College London and principal investigator of the JUICE magnetometer.

As we understand it on Earth, life needs liquid water, a source of heat and organic matter, “and then those first three things have to be stable enough over a long period of time that something can happen,” Dougherty says.

The JUICE mission will fly by the moon Europa twice. Credit: European Space Agency

“With [la] Juice, we want to confirm the presence of liquid water on these moons and find their heat sources. Other organs can be detected remotely if there is organic material on the surface. It’s about bringing all these ingredients together,” he explains.

Survive Jupiter

The truck-sized spacecraft Juice is designed to withstand the long journey to Jupiter and its extreme conditions. Two cross-shaped solar panels power the ship and forward chambers protect its most sensitive electronic components.

The mission is led by ESA (European Space Agency) and includes contributions from NASA and the Japan Aerospace Exploration Agency. Testing and modeling of Jupiter’s radiation belts allowed engineers to predict what Jupiter would encounter.

“The main achievement of this model for us was that it proved that what at first appeared to be a dangerous place was completely out of reach,” said Christian Erd, JUS spacecraft and systems manager, in a statement. “We have a lot of experience in managing radiation exposure, like a telecommunications satellite in geostationary Earth orbit for about three and a half years, 20 years on Jupiter.”

The JUICE mission could investigate why each Jupiter moon, such as Callisto, has a different surface. Credit: European Space Agency.

To help Zeus survive, his mission is designed to fly past Callisto 21 times and Europa twice. Europa is the closest moon to Jupiter and lies within the halo of its radiation. Two orbits of that moon would see the spacecraft experience about a third of its total radiation.

Some of Jus’s instruments are shielded, while others are exposed to the elements to study the atmospheres of Jupiter and its moons. Multiple images and sensors capture and transmit data at different wavelengths.

Considering the final distance between the spacecraft and Earth, it would take 45 minutes to send a one-way signal to Jupiter. But that’s nothing compared to the years it takes for the juice to reach Jupiter.

Scientists are already looking forward to the unique data the JUICE mission will provide.

“I think Ganymede’s first flyby was a very important moment,” Dougherty says. “We’re going to confirm there’s an ocean during the first one or two flybys.”

CNN’s Katie Hunt contributed to this report.