ESA’s JUICE On its Way to Jupiter

The European Space Agency’s Jupiter Icy Moons Explorer, or JUICE, began its 8-year journey to Jupiter this morning. The spacecraft needs five gravity assists so will not arrive until 2031. Once there, it will perform a detailed examination of Ganymede, the only moon in the solar system known to have a magnetosphere. JUICE will also study two other icy Jovian moons, Callisto and Europa, the latter in concert with NASA’s Europa Clipper.

Liftoff from Europe’s Guiana Space Centre in Kourou, French Guiana on the northeast coast of South America was on time at 9:14 am local time (8:14 am EDT). The launch was originally scheduled for yesterday, but the risk of lightning forced a one-day delay.

A little over an hour after launch, the spacecraft was on its way with solar arrays unfurled and communications established with the European Space Operations Centre in Darmstadt, Germany.

JUICE is taking a circuitous path to Jupiter, making flybys of the Earth, including the first lunar-Earth gravity assist, and Venus to slingshot its way to Jupiter. Arriving there in July 2031, it will go into orbit around Jupiter and make flybys of Ganymede, Europa and Callisto, then transfer into an orbit around Ganymede, the first spacecraft to transfer from orbiting a planet to orbiting one of its moons. JUICE will collect detailed data about Ganymede from an orbit just 500 kilometers above the surface before crashing into it at the end of its mission in 2035.

JUICE does not carry life-detection sensors, but will try to determine if Ganymede might be habitable. All three moons are thought to have liquid oceans under their icy crusts. Life as we know it requires water, fueling speculation that some type of microscopic life might be able to exist there.

NASA is focused on Europa. The Europa Clipper spacecraft is scheduled for launch next year by a SpaceX Falcon Heavy. Because Falcon Heavy is more powerful than Ariane 5, Europa Clipper needs fewer gravity assists and will reach Jupiter in April 2030, before JUICE.  It will orbit Jupiter, but make nearly 50 flybys of Europa, getting as close as 25 kilometers from the surface and perhaps flying through geysers that spew material from the subsurface ocean out in to space.