The European Juice Mission faces an unprecedented challenge in ten days: to pass through the “corridor” between the Moon and the Land in just 24 hours and capture energy from their gravity fields to head towards Venusin a complex system of braking and acceleration maneuvers never before performed in space.
The maneuvers, designed and worked on by research centers around the world for a whopping 20 years, will take place between August 19 and 20, and the group of scientists from the European Space Agency those in charge of directing them announced today at a press conference that Juice’s trajectory is already “adjusted and prepared” for the feat.
The probe will fly by the Moon on August 19 at 11:16 p.m. Spanish peninsular time, and 25 hours later, at 11:57 p.m. Spanish peninsular time on August 20, it will fly by Earth.
The Jupiter Icy Moons Explorer mission: Juice was launched on April 14, 2023, with a duration of eight years and the ambitious goal of exploring the environment of Jupiter and its 3 large ocean moons: Europa, Callisto and Ganymede (the largest and the only one with an internal magnetic field).
Given the technical impossibility of sending Juice directly to the giant Jupiter, researchers have spent two decades devising a panoramic trip in which the craft would use the energy obtained through the gravity of other planets to adjust its trajectory in space.
The high-precision goal is to keep Juice on the right track for eight years to complete its study of the environment around Jupiter, 800 million kilometres from Earth, and its three large moons by 2031.
Braking and accelerating between planets
The first major milestone of the mission will be this first flight between the Moon and the Earth: “It will be like going through a very narrow corridor, very, very quickly, and stepping on the accelerator to the maximum when the margin at the edge of the road is just millimetres,” said Juice’s Director of Operations, Ignacio Tanco.
This “braking” maneuver, unprecedented in space, is a way of shortcutting through the inner Solar System, and although the risk is very high, since the slightest error could deviate Juice from its route and mean the end of the mission, researchers are optimistic that it will be carried out successfully.
“We will monitor every second of the journey day and night, and make the necessary small adjustments to keep the ship on the right course,” said Nicolas Altobelli, head of scientific development at Juice.
Researchers have designed up to 6 different trajectory correction modes so that nothing is left to chance.
Unprecedented opportunity for remote sensing
The Moon-Earth flyby will provide a prime testing environment to activate the spacecraft’s ten scientific instruments and collect and analyze data from a real surface in space for the first time.
For some of these instruments, this will be the only opportunity to make certain measurements during the eight-year journey to Jupiter.
The flyby of the Moon around Earth is especially crucial, among other things, to fine-tune the RIME (Radar for Icy Moon Exploration) instrument before reaching Jupiter, since it is being affected by noises inside the spacecraft.
At its closest approach to the Moon, RIME will have eight minutes to observe alone, with all other instruments off or in silent mode, and based on these observations, it will develop an algorithm to correct its noise problem.
Repairing it is essential because RIME will be used to study the surface and subsurface of icy moons in order to identify areas where there may be water reserves that could be of interest to future missions.
In addition to the precision of the maneuvers, scientists have focused on ensuring that the adjustment of the ten instruments that will debut on August 19-20 during the approach to the Moon is perfect.
Observation will begin one hour before approaching Earth’s satellite, will last 15 minutes of maximum approach to the surface, and will continue for one hour after the spacecraft begins to move away and head towards Venus, which it will approach in August 2025.