ESA's JUICE mission successfully lift-off from French Guiana.

The Juice (Jupiter Icy Moons Explorer) is ready for the challenge. The main goal of that mission is to research and explore the secrets of Jupiter's icy moons Io, Europa, Ganymede, and Callisto. Each of those icy moons involves more water than on Earth. And at least in Europa is the ocean, which means there could be lifeforms. The magnetic fields of those moons mean that they could offer harbor for very special lifeforms that are very similar to the first bacteria on Earth. 

The thing that makes water liquid on those moons is Jupiter's tidal forces. And in some vision of the future, during space missions, the first colonists could create a space station in the oceans of those icy moons. The water layer protects the crew against powerful cosmic radiation. But that thing requires that the flow of water would be slow enough. 

Juice's lift-off from French Guayana. 

"ESA’s latest interplanetary mission, Juice, lifted off on an Ariane 5 rocket from Europe’s Spaceport in French 09:14 local time/14:14 CEST on April 14 2023 to begin its eight-year journey to Jupiter, where it will study in detail the gas giant planet’s three large ocean-bearing moons: Ganymede, Callisto, and Europa. Credit: ESA – M. Pédoussaut" (ScitechDaily.com/Jupiter’s Icy Enigmas: ESA’s Juice Launches on a Cosmic Treasure Hunt)

In the artist’s impression of Juice, which is not to scale, Ganymede is shown in the foreground, Callisto to the far right, and Europa center right. Volcanically active moon Io is also shown, at left. The moons were imaged by NASA’s Galileo spacecraft; Jupiter is seen here with a vivid aurora, captured by the NASA/ESA Hubble Space Telescope. Credit: Spacecraft: ESA/ATG medialab; Jupiter: NASA/ESA/J. Nichols (University of Leicester); Ganymede: NASA/JPL; Io: NASA/JPL/University of Arizona; Callisto and Europa: NASA/JPL/DLR  (ScitechDaily.com/Jupiter’s Icy Enigmas: ESA’s Juice Launches on a Cosmic Treasure Hunt)

"Overview of ESA and NASA missions that have visited or will visit Jupiter.

On the left of the timeline are spacecraft designed to orbit the gas giant, with the stated date range from arrival at Jupiter to end of mission. On the right of the timeline are spacecraft that have flown by Jupiter on their way to the more distant reaches of the Solar System; the stated dates show the year that the spacecraft flew past the gas giant".(ScitechDaily.com/Jupiter’s Icy Enigmas: ESA’s Juice Launches on a Cosmic Treasure Hunt)

"ESA’s Jupiter Icy Moons Explorer (Juice) mission launched on April 14, 2023, to 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". (ScitechDaily.com/Jupiter’s Icy Enigmas: ESA’s Juice Launches on a Cosmic Treasure Hunt)

"Juice 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".(ScitechDaily.com/Jupiter’s Icy Enigmas: ESA’s Juice Launches on a Cosmic Treasure Hunt)

"The first person to view Jupiter and its largest moons through a telescope was Galileo Galilei in 1609. Over 400 years later and humanity’s ever-long desire to look up and explore worlds beyond our own lives on; Juice will carry a commemorative plaque, as a tribute to the Italian astronomer.

Credit: ESA (Acknowledgement: work performed by ATG under contract to ESA), CC BY-SA 3.0 IGO"(ScitechDaily.com/Jupiter’s Icy Enigmas: ESA’s Juice Launches on a Cosmic Treasure Hunt)

"ESA’s Ariane 5, manufactured by ArianeGroup, has been in operation since 1996 and has already completed more than 100 launches from Europe’s Spaceport in French Guiana. It is 53 m high and 5.4 m in diameter with a liftoff mass of 780 tonnes.The Jupiter Icy Moons Explorer (Juice) will be the last ESA mission to launch on an Ariane 5 before Ariane 6 takes over. Credit: ESA (Acknowledgment: work performed by ATG under contract to ESA), CC BY-SA 3.0 IGO" (ScitechDaily.com/Jupiter’s Icy Enigmas: ESA’s Juice Launches on a Cosmic Treasure Hunt)

"ESA’s Jupiter Icy Moons Explorer (Juice) is set to embark on an eight-year cruise to Jupiter starting in April 2023. The mission will investigate the emergence of habitable worlds around gas giants and the Jupiter system as an archetype for the numerous giant planets now known to orbit other stars.

On its journey, Juice will make a series of flybys of Earth, the Earth-Moon system and Venus to set it on course for its July 2031 rendezvous in the Jovian system. Juice will make three Earth flybys during its cruise: one of the Earth-Moon system in August 2024, one of Earth in September 2026, and once again one of Earth in January 2029".(ScitechDaily.com/Jupiter’s Icy Enigmas: ESA’s Juice Launches on a Cosmic Treasure Hunt)

"In total Juice will spend approximately eight years cruising to Jupiter. It will reach Jupiter in July 2031, but will already begin making scientific observations six months before entering orbit around Jupiter. Juice will go on to spend many months orbiting Jupiter, making 35 flybys of icy moons Europa, Ganymede and Callisto, and finally conducting an orbital tour of Ganymede.

Credit: ESA (Acknowledgment: work performed by ATG under contract to ESA), CC BY-SA 3.0 IGO" (ScitechDaily.com/Jupiter’s Icy Enigmas: ESA’s Juice Launches on a Cosmic Treasure Hunt)

And another requirement for those stations is there are no lifeforms in those oceans. If there are lifeforms that thing limits the use of that water. Then those icy moons' water could use as fuel for small rockets that are taking samples from those moons and research the Jupiter system. In that system, the electrolysis will split water molecules into hydrogen and oxygen. 

That is suitable for rocket fuel. When we think of the possibility that some kind of submarine will send to those moon's oceans that system could be a rocket that lands on the ice layer. And then it simply melts the ice hole by using its rocket engines. Then the craft can operate under the ice by using the propellers. The rocket could look like the rocket from the Tintin cartoon. The pontoons and propellers are the chambers around the main engine. 

The system can use a rocket engine or resonance to break the hole in the ice. And then it can fill the water tanks that take it into the water where it travels by using propellers. The system can also use MHD (Magneto-Hydrodynamic Drive) while it operates underwater. When that futuristic rocket submarine must change its moon, it can make a hole in the ice and then rise by using a rocket engine. This kind of thing could be possible in the future. 

The Juice-mission profile is on film above this part of the text. 

As you see the long travel to Jupiter is a problem. The Juice probe will be there in 2031. And that means for making colonies on Jupiter and its icy moons requires more effective rocket technology than we use today. One of the reasons why flight time to that planet is so long is that the craft must slow its speed before it can place itself in the orbital trajectory. When the probe slows it's speed. It must use the brake engine or so-called gravitational brake. 

If a craft uses brake engines it must use the same fuel mass or create as much energy as it as it used to travel to that planet. In that version, the craft requires very much fuel. That it can transform into energy. The gravitational brake is an oppositely operating gravitational sling that is used to send probes to the outer solar system. In the journey's first stage, the Juice probe uses a gravitational sling to give enough energy to it. That it can travel to the Jupiter system. 

In gravitational brake, the spacecraft travels past the gravitational center. And then that gravitational center will pull it backward like Yoyo. The craft would slow its speed by benefiting the Sun's and Jupiter's gravitational fields. So, at first, the Juice probe benefits the inner planet's and the Sun's gravitational field to increase its speed. 

And then in the final part of the stage where it takes its position on Jupiter's orbiter, the probe will slow its speed by using a gravitational brake. One version of that thing is the position where Jupiter, its moons, and the Sun are in the line. And that gravitational situation slows its speed.  

https://scitechdaily.com/jupiters-icy-enigmas-esas-juice-launches-on-a-cosmic-treasure-hunt/