The scientific instruments of the “Juice” probe are a “technology marvel”.

Do Jupiter’s icy moons help life emerge? That is the question that juice Will try to answer During his mission in the Jovian system. For this purpose, the ESA probe has ten instruments designed to carry out its scientific research, but also to survive in the harsh environment of Jupiter. Overview of these latest devices.

Depiction and composition of Jupiter and its moons

To get an accurate picture of the Jovian system, scientists use so-called remote sensing instruments. The Janus Optical Camera provides images of Jupiter and its moons to help map them and study their morphology. Three other instruments will study the light emitted by the planet and its satellites. This “spectrum” makes it possible to deduce their composition. Majis’ visible and infrared spectrometer analyzes the surface of the moons for minerals or organic elements, while the very high resolution of the sub-millimeter-brightness SWI measures the electrical, physical and thermal properties, as well as on their surface compared to those in their atmospheres. The UVS spectrometer is concerned with the composition of atoms and molecules in the upper atmosphere. “ All of these items give an overview of the properties of the atmosphere, the environment of Jupiter and its moons, and its components. Olivier Weetas, scientific director of the mission.

study Jupiter system environment

Three devices On site, which has been specially adapted for Jupiter, will study the particles, magnetic fields and plasmas of the planetary system, and the physical elements that make it up. The J-MAG magnetometer measures the magnetic field of satellites to understand its physical properties, but also to study the properties of the oceans under the ice. “ At the core of its mission, Juice will be in orbit around GanymedeExplains Olivier Witassi. This is particularly interesting because, because Ganymede generates its own magnetic field, it is the only moon in the solar system in this state. Its measuring instruments were mounted on an eleven-meter boom outside the lander so that it would not be disturbed by other mission instruments. The RPWI instrument will focus on electrical signal emissions to measure electromagnetic fields and study the environment of Jupiter’s plasma (lightning, aurora borealis, etc.). This plasma environment is also the subject of a study by PEP, which measures particles, their flux, and their densities to understand their complex workings as well as the interactions of Jupiter’s magnetic field with the icy moons. “ These different indirect approaches, once the data are collected, will allow us to really understand where we are and in what context the probe is developing. The world abounds.

Topography of the surface and internal structure

Used in flight at low altitudes, geophysical instruments are used to explore the surface of Jupiter’s moons and the subsoil. The Gala laser altimeter sends laser pulses to the surface of the moons, which, once in contact with Earth, are sent back to the probe. This technology makes it possible to “topograph” and obtain a 3D representation of the target lunar surface. Meanwhile, Rime’s radar is interested in what’s happening under the ice of Ganymede, Europa, and Callisto. ” We send low-frequency electromagnetic waves that propagate through the ice as deep as nine kilometersexplains Lorenzo Bruzon, principal investigator for Radar. The echo these waves send, captured using a sixteen-meter antenna, allows us to create a profile of the basement structure and make an inventory of what is under the snow. , starting with the presence of liquid water. . So the whole allows us to estimate how habitable it is. For its part, the 3GM radio wave experiment, which consists of an oscillator for sounding the atmosphere and a transponder for measuring the speed of juice, studies the gravity of different moons.

Power supply and device protection: key challenges

juice It is a machine that is twenty-seven meters long and weighs six tons, more than half of which (3.5 tons) is devoted only to its propellant, the fuel that propels it from Earth into the orbit of Ganymede and which will make it possible to adjust the trajectory of the probe as needed. But it will face extreme conditions in the Jupiter system. “The large temperature differences and strong radiation field where the mission is going is hurting the technology “, confirms Christian Erd, head of the investigation. “ To protect them as much as possible, the most sensitive instruments are grouped in the center of the probe and protected by a layer of lead weighing more than 100 kilograms. “, the researcher continues.

The problem also arises for the 10 solar panels, the mission’s main source of power. The survival of the probe depends on the survival of the mission. “ It is covered with a thin layer of glass, made specifically of gallium arsenide to reduce the effect of radiation “, the researcher explains. They are deployed over an area of ​​85 square meters, and generate 800 watts of power (equivalent to a toaster) to supply the power needed for the various devices. Their deployment is also one of the rover’s first operations after launch to ensure proper functioning.” It is a marvel of technologyOlivier gets excited and sad. We cover b juicealmost all scientific fields. It’s not every day we launch a mission like this. »