4.9 KiB
| title | chunk | source | category | tags | date_saved | instance |
|---|---|---|---|---|---|---|
| Jupiter Icy Moons Explorer | 1/4 | https://en.wikipedia.org/wiki/Jupiter_Icy_Moons_Explorer | reference | science, encyclopedia | 2026-05-05T13:18:32.966259+00:00 | kb-cron |
The Jupiter Icy Moons Explorer (Juice, formerly JUICE) is an interplanetary spacecraft developed by the European Space Agency (ESA) and on its way to orbit and study three icy moons of Jupiter: Ganymede, Callisto, and Europa. These planetary-mass moons are planned to be studied because they are thought to have significant bodies of liquid water beneath their frozen surfaces, which would make them potentially habitable for extraterrestrial life. Juice is the first interplanetary spacecraft to the outer Solar System planets not launched by the United States and the first set to orbit a moon other than Earth's Moon. Launched by ESA, from Guiana Space Centre in French Guiana on 14 April 2023, with Airbus Defence and Space as the main contractor, it is expected to reach Jupiter in July 2031 after four gravity assists and eight years of travel. In December 2034, the spacecraft will enter orbit around Ganymede for its close-up science mission. Its period of operations will overlap with NASA's Europa Clipper mission, which was launched in October 2024.
== Background ==
The mission started as a reformulation of the Jupiter Ganymede Orbiter proposal, which was to be ESA's component of the cancelled Europa Jupiter System Mission – Laplace (EJSM-Laplace). It became a candidate for the first L-class mission (L1) of the ESA Cosmic Vision Programme, and its selection was announced on 2 May 2012. In April 2012, Juice was recommended over the proposed X-ray telescope ATHENA and the gravitational wave observatory LISA (under the older name NGO). Both unsuccessful mission proposals were selected later and are under development as of 2025. In July 2015, Airbus Defence and Space was selected as the prime contractor to design and build the probe, to be assembled in Toulouse, France. In 2024, Airbus Defence and Space received the Excellence Award from ESA for their work on Juice. By 2023, the mission was estimated to cost ESA 1.5 billion euros ($1.6 billion).
== Spacecraft ==
The main spacecraft design drivers are related to the large distance to the Sun, the use of solar power, and Jupiter's harsh radiation environment. The orbit insertions at Jupiter and Ganymede and the large number of flyby manoeuvres (more than 25 gravity assists, and two Europa flybys) require the spacecraft to carry about 3,000 kg (6,600 lb) of chemical propellant. The total delta-V capability of the spacecraft is about 2,700 m/s (6,000 mph). Juice has a fixed 2.5 meter diameter high-gain antenna and a steerable medium-gain antenna; both X- and K-band will be used. Downlink rates of 2 Gb/day are possible with ground-based Deep Space Antennas. On-board data storage capability is 1.25 Tb. The Juice main engine is a hypergolic bi-propellant (mono-methyl hydrazine and mixed oxides of nitrogen) 425 N thruster. A 100 kg multilayer insulation provides thermal control. The spacecraft is 3-axis stabilized using momentum wheels. Radiation shielding is used to protect onboard electronics from the Jovian environment (the required radiation tolerance is 50 kilorad at equipment level). The Juice science payload has a mass of 280 kilograms (620 lb) and includes the JANUS camera system, the MAJIS visible and infrared imaging spectrometer, the UVS ultraviolet imaging spectrograph, RIME radar sounder, GALA laser altimeter, SWI submillimetre wave instrument, J-MAG magnetometer, PEP particle and plasma package, RPWI radio and plasma wave investigation, 3GM radio science package, the PRIDE radio science instrument, and the RADEM radiation monitor. A 10.6 meters (35 ft) deployable boom will hold J-MAG and RPWI, a 16 meters (52 ft) long deployable antenna will be used for RIME. Four 3 meters (9.8 ft) booms carry parts of the RPWI instrument. The other instruments are mounted on the spacecraft body, or for 3GM, within the spacecraft bus.
== Mission timeline ==
=== Launch ===
Juice was launched into space on 14 April 2023 from the Guiana Space Centre on an Ariane 5 rocket. This was the final launch of an ESA science mission using the Ariane 5 vehicle, and the second to last launch of the rocket overall. The launch was originally scheduled for 13 April 2023, but due to poor weather the launch was postponed. The next day a second launch attempt succeeded, with liftoff occurring at 12:14:36 UTC. After the spacecraft separated from the rocket, it established a successful radio signal connection with the ground at 13:04 UTC. Juice's solar arrays were deployed about half an hour later, prompting ESA to deem the launch a success. During post-launch commissioning of the spacecraft, the RIME antenna failed to properly deploy from its mounting bracket. After several weeks of attempts to free the instrument, it was successfully deployed on 12 May of the same year.
=== Earth-Moon system flyby ===