ESA's GOCE probe takes shortcut to Jupiter

The road to Jupiter is long, which is why the European Space Agency's JOCE space probe is using other celestial bodies to slow, accelerate and change its path.

Darmstadt – The space probe “JOCE” has been on its way to the planet since April 2023 Jupiter and its moonsBut the probe is now owned by the European Space Agency. Issa The first is the “homeland” which is the land and moon It came very soon. There's a very special reason for that: the road to Jupiter is long and the probe used the Earth and the Moon to change its direction.

Juice – short for Jupiter Icy Moons Explorer – came close to Earth: On August 20, it flew over Southeast Asia and the Pacific Ocean at an altitude of just 6,840 kilometres. It took some pictures with its cameras and collected data with eight of the 10 scientific instruments. “Everything went smoothly, and we were thrilled to have Juice back so close to Earth,” says Ignacio Tanco, who is responsible for the mission as ESA’s spacecraft operations manager.

ESA's Juice space probe flies past Moon and Earth

Almost 24 hours before the flyby, the Joyce had already flown close to the Moon. According to the European Space Agency, the spacecraft's speed increased by 0.9 kilometers per second compared to the flight that passed close to the Earth's satellite. sunIn addition, the “juice” was directed towards the Earth. The flight of the Sun reduced the speed of the “juice” by 4.8 km/s relative to the Sun and changed its path by 100 degrees.

Jupiter – the target of the ESA space probe – is located on average about 800 million kilometres from Earth. For a direct path, the probe would have to have much more fuel on board than is possible. That’s why “Juice” uses other planets to change its trajectory and, above all, to gain momentum. However, the flyby of the Earth and the Moon was not used to gain higher speed. On the contrary: it slowed the space probe down.

The JOCE space probe took a “shortcut” through the inner solar system.

However, there was something more important: the “juice” is now on a direct path to Venus – which will be used to gain momentum in August 2025. Two more flybys of the Earth are also scheduled for September 2026 and January 2029, again to build momentum. If ESA had used the Earth and Moon flybys to gain momentum, it would have been a long time waiting for the next flyby of the planet (… Mars) You'll have to wait, the space agency wrote on its website. Instead, you now have a “shortcut” through the interior. Solar System taken.

Flying past the Earth and the Moon – what seems so simple is actually a complex maneuver that has never been done before, the European Space Agency confirms. However, the risky flyby of two celestial bodies saved about 100 to 150 kilograms of fuel.

ESA tests JOICE space probe instruments on Earth and Moon

In the coming weeks, ESA wants to publish images taken by the Juice instruments of the Moon and Earth, including those taken by the high-resolution camera JANUS. “The timing and location of this double flyby allow us to conduct a comprehensive study of the behaviour of the Juice instruments,” says Claire Vallat, mission operations scientist.

The data can now be used to prepare the instruments needed for their arrival at Jupiter. “Because we know the physical properties of the Earth, the Moon and the space environment so well, this is also the perfect place to understand how the instruments will respond to a real target,” Vallat said. (unpaid invoice)