Juice spacecraft embarks on historic Earth-Moon flyby journey

ESA’s Juice spacecraft recently completed an important maneuver on its journey to Jupiter. The spacecraft, which launched in April 2023, is set to make detailed observations of the gas planet and its three large moons. However, reaching Jupiter is no easy task due to the Sun’s massive gravitational pull. Missions to gas planets like Jupiter require gravity-assist maneuvers to gain energy from the gravitational fields of other planets.

Juice’s first boost will come from its home planet, Earth, during a flyby in August 2024. But before that, Juice had to perform a significant maneuver on November 17, 2023. Using its main engine, the spacecraft changed its orbit around the Sun to align itself for the Earth-Moon double gravity assist next summer. This maneuver lasted 43 minutes and consumed almost 10% of Juice’s fuel reserve. It was the first part of a two-part maneuver that will likely be the last time Juice’s main engine is used until its arrival in the Jupiter system in 2031.

Burning such a significant amount of fuel may seem excessive, but it’s essential for the mission’s success. By investing the fuel now, Juice won’t need to use its main engine again until it enters orbit around Jupiter in 2031. Instead, smaller thrusters will be used for trajectory corrections along the way. This strategy reduces the amount of fuel needed for the spacecraft and allows for more scientific instruments to be onboard.

The journey to Jupiter includes several flybys of different planets and moons. After the Earth-Moon double flyby in 2024, Juice will make a flyby of Venus in 2025 and two further flybys of Earth in 2026 and 2029. Each flyby provides the spacecraft with additional energy that helps it overcome the Sun’s gravity and climb towards Jupiter.

The recent maneuver was crucial not only for aligning Juice’s trajectory but also for testing the main engine’s functionality. It was the first time the engine was used for such a significant maneuver in deep space. Monitoring the behavior of the fuel during acceleration is important to ensure the spacecraft stays on course.

The next critical maneuver will be the “Jupiter Orbit Insertion” in 2031. Juice will need to slow down by about 1 km/s to enter orbit around Jupiter. This maneuver will be overseen by the teams at ESA’s ESOC mission control center. Once in orbit, Juice will conduct 35 flybys of the ocean moons, providing valuable data to better understand these mysterious worlds.

For those interested in learning more about the Juice mission, a feature-length film called “The Making of Juice” will premiere on ESA’s YouTube channel on November 23, 2023. Regular updates on the mission can be found on ESA’s social media channels.

Juice’s journey to Jupiter is a testament to the ingenuity and perseverance of scientists and engineers. By utilizing gravity-assist maneuvers and careful planning, Juice is set to unlock the secrets of Jupiter and its moons, paving the way for future space exploration.