JUICE (Jupiter Icy Moons Explorer) by European Space Agency: status and timeline

JUICE (Jupiter Icy Moons Explorer)

Find out whether Jupiter's icy moons hold liquid-water oceans that could support life, by mapping their ice shells, oceans and magnetic fields up close.

DeployStage 4 of 5

Cruising to Jupiter after a second Earth flyby on 28 Sep 2026; one more Earth flyby in Jan 2029.

Updated 13d agoChecked 11 Oct0 updates this week

Milestones

Next · Final Earth flyby

Launched on Ariane 5 from Kourou14 Apr 2023Complete.
Stuck RIME radar antenna freed and deployed12 May 2023Complete.
First double flyby of Moon and EarthAug 2024Complete.
Venus flyby31 Aug 2025Complete.
Second Earth flyby, 8,640 km over the Indian Ocean28 Sep 2026Complete.
Final Earth flybyTarget Jan 2029Current milestone.
Arrival in orbit around JupiterTarget Jul 2031Not yet reached.
Enter orbit around GanymedeTarget Dec 2034Not yet reached.

Most important updates

Upcoming

Jan 2029Final Earth flybyin about 116 weeks (next)
Jul 2031Arrival in orbit around Jupiter
Jul 2031Jupiter orbit insertion
Dec 2034Enter orbit around Ganymede

Current obstacles

Eight-year cruise with no margin for faultsIt must survive years of flybys before any Jupiter science. A 2025 timer bug cut contact for 20 hours before the Venus pass.
Jupiter's radiation beltsElectronics must tolerate intense radiation for years in the Jupiter system, which limits how close and how often it can pass Europa.

Physics limits

Rocket fuel can't reach Jupiter directlyReaching Jupiter needs more speed than a heavy probe can carry as fuel, so missions borrow it from planetary flybys, at the cost of years of cruise.
Sunlight fades with the square of distanceJupiter is about five times farther from the Sun than Earth, so each square metre of panel collects roughly a twenty-fifth of the power, forcing enormous arrays and a tight power budget.
Radio data rates fall with distanceA radio signal spreads out over hundreds of millions of kilometres, so even a 2.5 m dish returns data slowly and the probe must choose what to send home.

How it works

4 parts

Route

Slingshots instead of fuel

Flybys of the Moon, Earth, Venus and Earth again bend its path and add speed. The 2026 Earth pass alone added 3.5 km/s, fuel it could never carry.

Power

Huge solar wings

Sunlight at Jupiter is about 25 times weaker than at Earth, so ten panels totalling 85 m², 27 m tip to tip, yield only about 850 W there.

Tour

35 moon flybys, then Ganymede

After arriving in 2031 it loops past Ganymede, Callisto and Europa, then settles into orbit around Ganymede, the only moon with its own magnetic field.

Science

Radar, cameras and magnetometer

Ten instruments map surfaces, sound the ice with radar and measure magnetic and gravity signals that can reveal salty oceans underneath.

Spec sheet

Spec	JUICE (Jupiter Icy Moons Explorer)
Launch mass	About 6,070 kg^R (reported)
Dry mass	2,420 kg^R (reported)
Propellant capacity	3,650 kg^R (reported)
Solar array area	85 m²^R (reported)
Power at Jupiter	About 850 W^R (reported)
Science instruments	10^R (reported)
High-gain antenna	2.5 m dish^R (reported)

^R reported by the company

Update log

2 updates

Mon 28 Sep

Major: JUICE completes second Earth flyby, gaining 3.5 km/s on its way to JupiterPressTest

Wed 16 Jul 2025

Minor: JUICE loses contact for 20 hours before Venus flyby; team fixes timer bug with blind commandsPressSoftware

About European Space Agency

The team behind JUICE (Jupiter Icy Moons Explorer)

European Space Agency

Hera mission, Copernicus, ECMWF, planetary defence

ESA is the European intergovernmental space agency with 23 member states. It operates Earth observation systems, the International Space Station, deep-space missions and the Ariane rocket family. The Hera mission is ESA's planetary-defence follow-up to NASA's DART impact test.

Develops Ariane rockets and Copernicus Earth-observation satellites; participates in the International Space Station.
Hera mission to asteroid Didymos measures how NASA's 2022 DART impact deflected it, validating planetary defence.
Multinational agency with 23 European member states; 2026 budget €8.26 billion.

esa.int (opens esa.int)Company profile →

Founded: 197551 yrs
Headquarters: France
Status: Government
Valuation: government
Works in: SpaceflightMoon & deep spaceComputing
Coverage: 4 programs · 10 updateslatest 1d agochecked 11 Oct
Partners: NASA (opens nasa.gov)
Suppliers: Airbus Defence and Space (opens airbus.com)Thales Alenia Space (opens thalesgroup.com)

Spec

JUICE (Jupiter Icy Moons Explorer)

Launch mass

About 6,070 kg^R (reported)

Dry mass

2,420 kg^R (reported)

Propellant capacity

3,650 kg^R (reported)

Solar array area

85 m²^R (reported)

Power at Jupiter

About 850 W^R (reported)

Science instruments

10^R (reported)

High-gain antenna

2.5 m dish^R (reported)