 Artist's impression ofJuice orbiting Jupiter | |||||||||||||||||||||||
| Names | Juice | ||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Mission type | Jupiter orbiter | ||||||||||||||||||||||
| Operator | European Space Agency | ||||||||||||||||||||||
| COSPAR ID | 2023-053A | ||||||||||||||||||||||
| SATCATno. | 56176 | ||||||||||||||||||||||
| Website | Official website | ||||||||||||||||||||||
| Mission duration |
| ||||||||||||||||||||||
| Spacecraft properties | |||||||||||||||||||||||
| Manufacturer | Airbus Defence and Space | ||||||||||||||||||||||
| Launch mass | 6,070 kg (13,380 lb)[1] | ||||||||||||||||||||||
| Dry mass | 2,420 kg (5,340 lb)[1] | ||||||||||||||||||||||
| Dimensions | 16.8 × 27.1 × 13.7 meters[1] | ||||||||||||||||||||||
| Power | 850 watts[1] | ||||||||||||||||||||||
| Start of mission | |||||||||||||||||||||||
| Launch date | 14 April 2023 12:14:36 UTC[2] | ||||||||||||||||||||||
| Rocket | Ariane 5 ECA+ (VA-260) | ||||||||||||||||||||||
| Launch site | KourouELA-3 | ||||||||||||||||||||||
| Contractor | Arianespace | ||||||||||||||||||||||
| Flyby ofMoon | |||||||||||||||||||||||
| Closest approach | 19 August 2024, 21:16 UTC | ||||||||||||||||||||||
| Distance | 700 km (430 mi) | ||||||||||||||||||||||
| Flyby of Earth | |||||||||||||||||||||||
| Closest approach | 20 August 2024, 21:57 UTC | ||||||||||||||||||||||
| Distance | 6,807 km (4,230 mi) | ||||||||||||||||||||||
| Flyby ofVenus | |||||||||||||||||||||||
| Closest approach | 31 August 2025, 05:28 UTC | ||||||||||||||||||||||
| Flyby of Earth | |||||||||||||||||||||||
| Closest approach | 29 September 2026 | ||||||||||||||||||||||
| Flyby of Mars | |||||||||||||||||||||||
| Closest approach | 18 January 2029 | ||||||||||||||||||||||
| Jupiter orbiter | |||||||||||||||||||||||
| Orbital insertion | July 2031 (planned) | ||||||||||||||||||||||
| Orbital departure | December 2034 (planned) | ||||||||||||||||||||||
| Ganymede orbiter | |||||||||||||||||||||||
| Orbital insertion | December 2034 (planned) | ||||||||||||||||||||||
| Orbital parameters | |||||||||||||||||||||||
| Periapsis altitude | 500 km (310 mi) | ||||||||||||||||||||||
| Apoapsis altitude | 500 km (310 mi) | ||||||||||||||||||||||
| |||||||||||||||||||||||
 Juice mission insignia | |||||||||||||||||||||||
TheJupiter Icy Moons Explorer (Juice, formerlyJUICE[3]) is aninterplanetary spacecraft developed by theEuropean Space Agency (ESA) and on its way to orbit and study threeicy moons ofJupiter:Ganymede,Callisto, andEuropa. Theseplanetary-mass moons are planned to be studied because they are thought to have significant bodies of liquid water beneath their frozen surfaces, which would make thempotentially habitable forextraterrestrial life.[4][5]
Juice is the first interplanetaryspacecraft to the outer Solar System planets not launched by theUnited States and the first set to orbit a moon other than Earth'sMoon. Launched by ESA, fromGuiana Space Centre inFrench Guiana on 14 April 2023, withAirbus Defence and Space as the main contractor,[6][7] it is expected to reach Jupiter in July 2031 after fourgravity assists and eight years of travel.[8][9] In December 2034, the spacecraft will enter orbit around Ganymede for its close-up science mission.[8] Its period of operations will overlap withNASA'sEuropa Clipper mission, which was launched in October 2024.[10]
The mission started as a reformulation of theJupiter Ganymede Orbiter proposal, which was to beESA's component of the cancelledEuropa Jupiter System Mission – Laplace (EJSM-Laplace).[11] It became a candidate for the first L-class mission (L1) of the ESACosmic Vision Programme, and its selection was announced on 2 May 2012.[12]
In April 2012,Juice was recommended over the proposedX-ray telescopeATHENA and thegravitational wave observatoryLISA (under the older name NGO).[13][14] Both unsuccessful mission proposals have been selected later and are under development as of 2025.[15][16][17]
In July 2015,Airbus Defence and Space was selected as the prime contractor to design and build the probe, to be assembled inToulouse,France.[18] In 2024, Airbus Defence and Space received the Excellence Award from ESA for their work onJuice.[19] By 2023, the mission was estimated to costESA 1.5 billion euros ($1.6 billion).[20]
The mainspacecraft design drivers are related to the large distance to the Sun, the use ofsolar power, and Jupiter's harsh radiation environment. The orbit insertions at Jupiter and Ganymede and the large number of flyby manoeuvres (more than 25gravity assists, and two Europa flybys) require the spacecraft to carry about 3,000 kg (6,600 lb) of chemical propellant.[21] The totaldelta-V capability of the spacecraft is about 2,700 m/s (6,000 mph).[22]
Juice has a fixed 2.5 meter diameter high-gain antenna and a steerable medium-gain antenna; bothX- andK-band will be used. Downlink rates of 2 Gb/day are possible with ground-based Deep Space Antennas. On-board data storage capability is 1.25 Tb.[1]
TheJuice main engine is ahypergolic bi-propellant (mono-methyl hydrazine andmixed oxides of nitrogen) 425 N thruster. A 100 kg multilayer insulation provides thermal control. The spacecraft is 3-axis stabilized usingmomentum wheels. Radiation shielding is used to protect onboard electronics from the Jovian environment[1] (the required radiation tolerance is 50kilorad at equipment level[22]).
TheJuice science payload has a mass of 280 kilograms (620 lb) and includes the JANUS camera system, the MAJIS visible and infrared imaging spectrometer, the UVS ultraviolet imaging spectrograph, RIME radar sounder, GALA laser altimeter, SWI submillimetre wave instrument, J-MAG magnetometer, PEP particle and plasma package, RPWI radio and plasma wave investigation, 3GM radio science package, the PRIDE radio science instrument, and the RADEM radiation monitor.
A 10.6 meters (35 ft) deployable boom will hold J-MAG and RPWI, a 16 meters (52 ft) long deployable antenna will be used for RIME. Four 3 meters (9.8 ft) booms carry parts of the RPWI instrument. The other instruments are mounted on the spacecraft body, or for 3GM, within thespacecraft bus.[1]
Juice was launched into space on 14 April 2023 from theGuiana Space Centre on anAriane 5 rocket. This was the final launch of an ESA science mission using the Ariane 5 vehicle,[6] and thesecond to last launch of the rocket overall.[23]
The launch was originally scheduled for 13 April 2023, but due to poor weather the launch was postponed.[24] The next day a second launch attempt succeeded, with liftoff occurring at 12:14:36 UTC. After the spacecraft separated from the rocket, it established a successful radio signal connection with the ground at 13:04 UTC.Juice's solar arrays were deployed about half an hour later, prompting ESA to deem the launch a success.[6]
During post-launch commissioning of the spacecraft, the RIME antenna failed to properly deploy from its mounting bracket.[25] After several weeks of attempts to free the instrument, it was successfully deployed on 12 May of the same year.[26]
In August 2024,Juice performed its firstgravity assist when it flew by theMoon and thenEarth, becoming the first ever spacecraft to perform such maneuver using both bodies. The closest approach to the Moon happened at 21:15 UTC on 19 August. This increased the spacecraft's speed by 0.9 km/s relative to the Sun, sending it towards Earth. The closest approach to Earth happened at 21:56 UTC on 20 August. This reduced the spacecraft's speed by 4.8 km/s relative to the Sun, sending it towardsVenus for the next gravity assist planned for August 2025. This double gravity assist saved the spacecraft up to 150 kg of fuel and deflected it by an angle of 100° compared to its path before the flyby.[27]
During this maneuver,Juice tested many of its scientific instruments. All 10 instruments were active during the Moon flyby, and eight during the Earth flyby. The JANUS camera took high-resolution images of the Moon and Earth.[27] The MAJIS and SWI instruments detected the expected chemical signatures ofhabitability on Earth and MAJIS also provided information-rich temperature maps of Earth.[28][29] Two sensors of the Particle Environment Package (PEP) took pictures andin situ measurements of the charged particle cloud surrounding Earth.[30] The RIMEradar sounder captured a radargram image of the patch of the lunar surface that is also visible in the famousEarthrise photo, taken in 1968 during theApollo 8 mission.[31]
On 16 July 2025, during a time-sensitive period before the plannedVenus flyby,Juice experienced a communication anomaly that temporarily severed the spacecraft's contact with Earth. After almost 20 hours of recovery efforts,ESOC andAirbus managed to resolve the issue and identified its root cause related to a scheduled restart of the spacecraft's internal timer. Plans for the flyby remained unchanged[32] andJuice successfully flew by Venus on 31 August 2025, with the closest approach of 5,088 km above Venus's surface at 05:28 UTC, performing agravity assist maneuver that increased its velocity by 5.1 km/s and sent it towards its second Earth flyby planned for September 2026. Due to thermal constraints (solar flux of 3,000 W/m2 near Venus versus 50 W/m2 nearJupiter), no imaging or scientific observations were planned for the Venus flyby and the spacecraft used its high-gain antenna as a thermal shield, pointing it toward the Sun.[33][34]
The interstellar comet3I/ATLAS, discovered in July 2025 as only the third knowninterstellar object in theSolar System, made its closest approach to the Sun in October 2025. However, this part of its trajectory, when it is expected to show strong cometary activity, was not visible from Earth-based telescopes as it occured on the other side of the Sun. In September 2025,ESA expected that of all its interplanetary spacecraft,Juice would have the best conditions for observing the object during its close approach to the Sun.[35][36]
ESA decided to commandJuice to attempt observing 3I/ATLAS in November 2025, at a distance of 0.428AU,[37] using its cameras, spectrometers, and a particle sensor. ESA was also considering coordinating ultraviolet spectrograph observations with NASA'sEuropa Clipper. Due to the challenging thermal conditions duringJuice's travel through the inner Solar System, the data from these observations were not expected to reach Earth before February 2026.[36][38][35] The commands for the observations were prepared atESOC on 24 October 2025.[39] The observations are being conducted between 2 and 25 November 2025. Thermal constraints limit the observations for no more than 30 minutes per day with the exception of the Particle Environment Package (PEP) which was commanded to operate for twelve days straight.[40]
Following the launch, multiplegravity assists are needed to putJuice on a trajectory to Jupiter:[8][6]
Juice passes through theasteroid belt twice. A flyby of the asteroid(223) Rosa was proposed to occur in October 2029, but was abandoned to save fuel for the primary Jovian mission.[42][43][44]
Gravity assists within the Jovian system include:[45]
The main characteristics of the Jupiter reference tour are summarised below (source: Table 5-2 of ESA/SRE(2014)1[22]). This scenario assumed an early June 2022 launch, however, thedelta-V requirements are representative due to the rather short, repetitive orbital configurations of Europa, Ganymede and Callisto.
| Event | Duration | Delta-V notes[22] |
|---|---|---|
| Jupiter orbit insertion: When it arrives in the Jovian system in July 2031,[8]Juice will first perform a 400 km (250 mi) Ganymede gravity assist flyby to reduce spacecraft velocity by ~300 m/s (670 mph), followed by ~900 m/s (2,000 mph) Jupiter orbit insertion engine burn ~7.5 hours later. Finally, a Perijove Raising Manoeuvre (PRM) burn atapoapsis will raise theperiapsis ofJuice's initial 13x243 Jovian radii elongated orbit to match that of Ganymede (15 Rj). | 186 days | 952 m/s (2,130 mph). |
| 2nd Ganymede flyby to initial encounter with Callisto: 2nd, 3rd and 4th Ganymede flyby to reduce the orbital period and inclination ofJuice's orbit, followed by 1st flyby of Callisto. | 193 days | 27 m/s (60 mph). |
| Europa phase: Starting in July 2032,[8] there will be two <400 km (250 mi) flybys of Europa followed by another Callisto flyby. The brief Europa encounters (during which the probe is expected to sustain a third of its lifetime radiation exposure[46]) are planned such that the radiation exposure is as low as possible, first by encountering Europa at perijove (i.e. the spacecraft's perijove is equal to Europa's orbital radius), and second by having only one low perijove passage per Europa flyby. | 35 days | 30 m/s (67 mph). |
| Inclined phase: ~6 further flybys of Callisto and Ganymede to temporarily increase the orbital inclination to 22 degrees. This will allow an investigation of Jupiter's polar regions andJupiter's magnetosphere[8] at the maximum inclination over a four-month period. | 208 days | 13 m/s (29 mph). |
| Transfer to Ganymede: A series of Callisto and Ganymede gravity assists will be performed to gradually reduceJuice's speed by 1,600 m/s (3,600 mph). Finally, a series of distant ~45,000 km (28,000 mi) flybys of the far side of Ganymede (near the Jupiter-Ganymede-L2Lagrange point) will further reduce the required orbital insertion delta-V by 500 m/s (1,100 mph). | 353 days | 60 m/s (130 mph). |
| Ganymede orbital phase: In December 2034,[8]Juice will enter an initial 12-hour polar orbit around Ganymede after performing a 185 m/s (410 mph) delta-V braking burn. Jupiter gravitational perturbations will gradually reduce the minimum orbital altitude to 500 km (310 mi) after ~100 days. The spacecraft will then perform two major engine firings to enter a nearly circular 500 km (310 mi) polar orbit, for a further six months of observations (e.g. Ganymede's composition andmagnetosphere).[8] The orbital phase includes a final stage at 200 km altitude.[47] At the end of 2035, Jupiter perturbations will causeJuice to impact onto Ganymede within weeks as the spacecraft runs out of propellant.[8] | 284 days | 614 m/s (1,370 mph). |
| Full tour (Jupiter orbit insertion to end of mission) | 1259 days | 1,696 m/s (3,790 mph). |
.jpg)
TheJuice orbiter will perform detailed investigations onGanymede and evaluate itspotential to support life. Investigations ofEuropa andCallisto will complete a comparative picture of theseGalilean moons.[48] The three moons are thought to harbour internalliquid water oceans, and so are central to understanding thehabitability of icy worlds.
The main science objectives for Ganymede, and to a lesser extent for Callisto, are:[48]
ForEuropa, the focus is on the chemistry essential to life, includingorganic molecules, and on understanding the formation of surface features and the composition of the non-water-ice material. The chemical investigations will be focused also on the question which chemicals originated underground and were brought to the surface bytectonics orcryovolcanism, and which arrived from above, originating at other places within the Jovian system.[49]
Furthermore,Juice will provide the first subsurface sounding of the moon, including the first determination of the minimal thickness of the icy crust over the most recently volcanically active regions.Juice will be able to determine if pockets of liquid water exist within the ice and possibly also probe the interface between the icy shell and the subsurface ocean.[49]
More distant spatially resolved observations will also be carried out for several minor irregular satellites and the volcanically active moonIo.Juice will monitor the volcanic activity of Io and study the composition of its surface materials. The mission will also observeJupiter's dusty rings and study their interactions with the small inner moons:Metis,Adrastea,Amalthea, andThebe.[50]
Juice will repeatedly mapJupiter's atmosphere and use its instruments to explore the poorly understood middle and upper atmosphere, focusing on the processes connecting the various layers and measuring, for the first time, the winds in Jupiter's middle atmosphere. This will expand our knowledge about the transport of energy between various regions of the atmosphere and illuminate the processes behind the longevity of theGreat Red Spot and other weather systems.Juice will also explore themagnetosphere of Jupiter in great detail and focus on its interactions with theGalilean moons, especially the processes transporting plasma fromIo to the icy moons.[50]
On 21 February 2013, after a competition, 10 science instruments (plus one experiment using the spacecraft's telecommunication system) were selected by ESA, which were developed by science and engineering teams from all over Europe, with participation from the US.[51][52][53][54] Japan also contributed several components for SWI, RPWI, GALA, PEP, JANUS, and J-MAG instruments, and will facilitate testing.[55][56][57]
The name isLatin for "comprehensive observation of Jupiter, his love affairs and descendants."[58] It is a camera system to image Ganymede and interesting parts of the surface of Callisto at better than 400 m/pixel (resolution limited by mission data volume). Selected targets will be investigated in high-resolution with a spatial resolution from 25 m/pixel down to 2.4 m/pixel with a 1.3° field of view. The camera system has 13 panchromatic, broad and narrow-band filters in the 0.36 μm to 1.1 μm range, and provides stereo imaging capabilities. JANUS will also allow relating spectral, laser, and radar measurements to geomorphology and thus will provide the overall geological context.
A visible and infraredimaging spectrograph operating from 0.5 μm to 5.56 μm, withspectral resolution of 3–7 nm, that will observe tropospheric cloud features and minor gas species on Jupiter and will investigate the composition of ices and minerals on the surfaces of the icy moons. The spatial resolution will be down to 75 m (246 ft) on Ganymede and about 100 km (62 mi) on Jupiter.[59]
Animaging spectrograph operating in the wavelength range 55–210 nm with spectral resolution of <0.6 nm that will characteriseexospheres andaurorae of the icy moons, including plume searches on Europa, and study the Jovian upper atmosphere and aurorae. Resolution up to 500 m (1,600 ft) observing Ganymede and up to 250 km (160 mi) observing Jupiter.
Aspectrometer using a 30 cm (12 in) antenna and working in 1080–1275GHz and 530–601 GHz with spectral resolving power of ~107 that will study Jupiter's stratosphere and troposphere, and the exospheres and surfaces of the icy moons.
Alaser altimeter with a 20 m (66 ft) spot size and 10 cm (3.9 in) vertical resolution at 200 km (120 mi) intended for studying topography of icy moons and tidal deformations of Ganymede.
Anice-penetrating radar working at frequency of 9 MHz (1 and 3 MHz bandwidth) emitted by a 16 m (52 ft) antenna; will be used to study the subsurface structure of Jovian moons down to 9 km (5.6 mi) depth with vertical resolution up to 30 m (98 ft) in ice.
Juice will study the subsurface oceans of the icy moons and the interaction of Jovian magnetic field with themagnetic field of Ganymede using a sensitivemagnetometer.
A suite of six sensors to study themagnetosphere of Jupiter and its interactions with the Jovian moons. PEP will measure positive and negative ions, electrons, exospheric neutral gas, thermalplasma andenergetic neutral atoms present in all domains of the Jupiter system from 1meV to 1MeV energy.
RPWI will characterise theplasma environment and radio emissions around the spacecraft, it is composed of four experiments: GANDALF, MIME, FRODO, and JENRAGE. RPWI will use fourLangmuir probes, each one mounted at the end of its own dedicated boom and sensitive up to 1.6 MHz, to characterize plasma, and receivers in the frequency range 80 kHz to 45 MHz to measure radio emissions.[60] This scientific instrument is somewhat notable for usingSonic the Hedgehog as part of its logo.[61][62]
3GM is a radio science package comprising aKa transponder and an ultrastableoscillator.[63] 3GM will be used to study the gravity field at Ganymede (up to 10 degrees), to determine the extent of internal oceans on the icy moons, and to investigate the structure of the neutral atmospheres and ionospheres of Jupiter (0.1 – 800 mbar) and its moons. 3GM carries an Israeli-builtatomic clock "that will measure tiny vacillations in a radio beam".[64][65]
The experiment will generate specific signals transmitted byJuice's antenna and received byvery-long-baseline interferometry to perform precision measurements of the gravity fields of Jupiter and its icy moons.
This article incorporates text from this source, which is in thepublic domain.
| Flybys |  | |
|---|---|---|
| Orbiters | ||
| Atmospheric probes | ||
| En route |
| |
| Planned missions |
| |
| Proposed missions |
| |
| Cancelled or not developed | ||
| Related topics | ||
Missions are ordered by launch date. Sign† indicates failure en route or before intended mission data returned.‡ indicates use of the planet as agravity assist en route to another destination. | ||
Articles related to Jupiter Icy Moons Explorer | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
.jpg)
.png)
