JUICE (Jupiter Icy Moons Explorer)

The European Space Agency (ESA) is ready to launch the Jupiter Icy Moons Explorer (JUICE), an extraterrestrial spacecraft, with Airbus Defence and Space serving as the lead contractor. The mission will focus on three of Jupiter’s Galilean moons: Ganymede, Callisto, and Europa. Read here to know more about the mission.

Long-standing theories among scientists suggest that Jupiter’s frozen moons may harbor life. In order to investigate whether there is life on Jupiter’s moons, conjecture is predicated on the idea that there is liquid water beneath the kilometers of ice sheets.

These moons are all thought to have sizable liquid water bodies beneath their surfaces, making them potentially habitable environments.

JUICE (Jupiter Icy Moons Explorer)

ESA’s Jupiter Icy Moons Explorer, Juice, will make detailed observations of the giant gas planet and its three large ocean-bearing moons – Ganymede, Callisto, and Europa – with a suite of remote sensing, geophysical and in situ instruments.

The mission will characterize these moons as both planetary objects and possible habitats, explore Jupiter’s complex environment in-depth and study the wider Jupiter system as an archetype for gas giants across the Universe.

Few other nations’ space agencies have partnered with ESA on various levels for the JUICE mission:

• NASA has contributed one instrument (UVS) and hardware for two European-provided instruments (RIME and PEP).
• JAXA has contributed hardware for various European-provided instruments (SWI, PEP, GALA, RPWI).

The mission will consider two key themes of ESA’s Cosmic Vision 2015-2025:

1. What are the conditions for planet formation and the emergence of life?
2. How does the Solar System work?

Under these themes, Juice will explore-

1. the habitable zone – namely characterizing the oceans, icy shells, compositions, surfaces, environments, and activity of Ganymede, Europa, and Callisto
2. the wider Jupiter system, characterizing Jupiter’s atmosphere, magnetic environment, ring system, and other satellites (including Io).

Launch

• Foreseen to launch from Europe’s Spaceport in Kourou, French Guiana, on an Ariane 5 launcher during a launch window in April 2023.

Journey and orbit

• JUICE will spend approximately eight years cruising to Jupiter, during which it will complete fly-bys of Venus, Earth, and the Earth-Moon system.
• It will reach Jupiter in July 2031; six months before entering orbit around Jupiter, Juice will begin its nominal science phase.
• The spacecraft will go on to spend many months orbiting Jupiter, completing fly-bys of Europa, Ganymede, and Callisto, and finally conducting an orbital tour of Ganymede

JUICE builds on the previously proposed Europa Jupiter System Mission (EJSM-Laplace), a planned collaborative mission between ESA and NASA that would have carried out an in-depth study of the Jovian system and its icy moons.

It is now foreseen that the Juice and NASA Europa Clipper spacecraft will be exploring the Jovian system simultaneously.

JUICE builds on scientific and technological heritage from previous space missions – including ESA’s Mars Express, Venus Express, Rosetta, and BepiColombo.

It will pave the way for future extensive exploration of the diverse extreme environments in the distant outer Solar System.

JUICE will push significantly beyond the capabilities of previous missions like NASA’s Galileo (1989-2003), and directly complement the results of NASA’s Juno mission (2011–).

What will JUICE explore?

JUICE will explore the secrets of Jupiter and tackle five key mysteries:

1. What are Jupiter’s Ocean worlds like?
2. Why is Ganymede so unique?
3. Could there be or ever have been life on the Jupiter system?
4. How has Jupiter’s complex environment shaped its moons and vice versa?
5. What is a typical gas giant planet like, how did it form, and does it work?

JUICE will be the first spacecraft to ever orbit a moon in the outer Solar System (Ganymede).

Jupiter and its moons

Jupiter is the fifth planet from our Sun and is, by far, the largest planet in the solar system which is more than twice as massive as all the other planets combined.

Jupiter’s stripes and swirls are actually cold, windy clouds of ammonia and water, floating in an atmosphere of hydrogen and helium.

Jupiter’s iconic Great Red Spot is a giant storm bigger than Earth that has raged for hundreds of years.

Jupiter is surrounded by dozens of moons. Jupiter also has several rings, but unlike the famous rings of Saturn, Jupiter’s rings are very faint and made of dust, not ice.

• Jupiter’s rings were first discovered by NASA’s Voyager 1 spacecraft in 1979.

Jupiter has the shortest day in the solar system. One day on Jupiter takes only about 10 hours (the time it takes for Jupiter to rotate or spin around once), and Jupiter makes a complete orbit around the Sun (a year in Jovian time) in about 12 Earth years (4,333 Earth days).

Its equator is tilted with respect to its orbital path around the Sun by just 3 degrees. This means Jupiter spins nearly upright and does not have seasons as extreme as other planets do.

Moons

Jupiter forms a kind of miniature solar system with four large moons and many smaller moons.

• Jupiter has 80 moons.
• Fifty-seven moons have been given official names by the International Astronomical Union (IAU).
• Another 23 moons are awaiting names.

Jupiter’s four largest moons – Io, Europa, Ganymede, and Callisto – were first observed by the astronomer Galileo Galilei in 1610 using an early version of the telescope.

• These four moons are known today as the Galilean satellites, and they’re some of the most fascinating destinations in our solar system.
• Io is the most volcanically active body in the solar system.
• Ganymede is the largest moon in the solar system (even bigger than the planet Mercury).
• Callisto’s very few small craters indicate a small degree of current surface activity.
• A liquid-water ocean with the ingredients for life may lie beneath the frozen crust of Europa, making it a tempting place to explore.

While planet Jupiter is an unlikely place for living things to take hold, the same is not true of some of its many moons.

• Europa is one of the likeliest places to find life elsewhere in our solar system. There is evidence of a vast ocean just beneath its icy crust, where life could possibly be supported.
• The JUICE mission aims to explore this possibility.

Missions to explore Jupiter

Jupiter is not only an interesting scientific destination but also an important waypoint for spacecraft heading further into the Solar System. The gas giant’s immense gravity field can provide a boost and trajectory change for spacecraft heading to even further destinations.

Past missions

• NASA’s New Horizons spacecraft was the first mission to fly past the Kuiper Belt worlds Pluto and Arrokoth.
• NASA’s Cassini mission orbited Saturn from 2004 to 2017, circling the planet 294 times and teaching us almost everything we know about our ringed neighbor.
• NASA’s Galileo was the first spacecraft to orbit Jupiter. It revealed the structure of the planet’s magnetic field and intense radiation belts, made the first detailed maps of Jupiter’s major moons, hinted at a possible underground ocean on Europa, sent the first probe to sample a gas planet’s atmosphere, and more.
• Voyager 1 and Voyager 2 launched in 1977 and each made a grand tour of the solar system before heading out of it.
• NASA’s Pioneer 10 and 11 are twin probes that helped illuminate the outer stretches of our solar neighborhood.

Active missions

• Juno, NASA’s Jupiter Probe is searching for answers about Jupiter’s origins and how has the gas giant changed over time.

Future missions

• NASA’s Europa Clipper will help us determine if Jupiter’s icy moon Europa could support life.
• The European Space Agency (ESA) is launching the JUICE spacecraft to study Jupiter and its three largest icy moons.

Challenges for the JUICE mission

JUICE will build on the scientific and technological advancements made by earlier NASA and ESA planetary missions.

The most difficult engineering issues are:

• the performance of the solar array in a cold and intense radiation environment
• protection of electronics against Jupiter’s harsh radiation environment
• electro­magnetic cleanliness on the spacecraft so as not to interfere with the sensitive measurements to be taken.

These issues are in addition to the programmatic challenges to maintain cost and schedule.

On the operation side, the mission controllers will need to perform complex satellite navigation in both the inner solar system and the Jupiter system.

Significance of JUICE mission

By studying Jupiter and its moons, JUICE will help astrobiologists understand how habitable worlds might emerge around gas giant planets.

• The largest natural satellite in the solar system, Ganymede, is highlighted in particular as a planetary body and prospective habitat.
• It offers a favorable setting for the study of potentially habitable planets and displays unusual magnetic and plasma interactions with its surroundings.
• For Europa, the focus is on the chemistry essential to life, including organic molecules, and on understanding the formation of surface features and the composition of the non-water-ice material.

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 active regions.

The JUICE mission will also characterize the diversity of processes in the Jovian system that may provide a stable environment on the icy moons at geologic time scales, including gravitational coupling between the Galilean moons and their long-term tidal influence on the system as a whole.

JUICE and Europa Clipper will provide ground-breaking information, through their monitoring of the Jovian system elements, about the planet’s atmosphere, magnetosphere, and plasma environment, and about the exospheres of the icy moons.

Understanding of the development and dynamics of the Jovian system will be improved by JUICE’s broad new observations of Jupiter’s atmosphere, magnetosphere, and interaction with the satellites.

JUICE is an extremely intriguing project that follows in the footsteps of the Cassini-Huygens mission since it allows international involvement of a significant number of individuals interested in a variety of significant science issues.

-Article written by Swathi Satish