Science and Exploration
August 21, 2024 31742 views 83 likes
ESA's Jupiter Icy Moons Explorer, JUICE, has become the first spacecraft to successfully complete a moon-Earth flyby en route to Venus, using Earth's gravity to travel through the inner solar system and get to Jupiter in a shortcut.
The closest approach to the Moon was at 23:15 CEST (21:15 UTC) on August 19, and Juice made its closest approach to Earth just over 24 hours later, at 23:56 CEST (21:56 UTC) on August 20.
The spacecraft flew 4,200 miles (6,840 km) over Southeast Asia and the Pacific Ocean, taking a series of images with its onboard surveillance cameras and collecting scientific data with eight of its 10 instruments.
“The gravity assist flyby was flawless, everything went without a hitch, and it was exciting to see Juice return so close to Earth,” said Ignacio Tanco, the mission's spacecraft operations manager.
The purpose of the flyby was to use gravity, first from the Moon and then from the Earth, to alter the spacecraft's speed and direction, thereby changing Juice's course through space.
Juice Surveillance Camera 1 captures beautiful crater details during lunar flyby
The Moon flyby increased Juice's speed relative to the Sun by 0.9 km/s, pointing Juice towards the Earth. The Earth flyby decreased Juice's speed relative to the Sun by 4.8 km/s, putting Juice on a new orbit towards Venus. Overall, the Moon and Earth flybys redirected Juice by an angle of 100° compared to its pre-flyby orbit.
The inherently risky flyby required ultra-precise real-time navigation, which saved the mission about 100-150 kg of fuel. A month before the flyby, spacecraft operators nudged Juice slightly to put it on precisely the right approach trajectory. They then tracked Juice around the clock from August 17 to 22.
Thanks to a flawless launch of Ariane 5 in April 2023, JUICE has a little extra fuel in its tanks, allowing it to get closer to Jupiter's moon Ganymede than originally planned. Successful flybys of the Moon and Earth have secured this bonus science.
“Thanks to extremely precise navigation by ESA's flight dynamics team, we only used a small fraction of the fuel we had set aside for this flyby, leaving more room for a rainy day and allowing us to extend the science mission once we reach Jupiter,” adds Ignacio.
Juice captured Earth's closest approach to the moon from afar
First experience with science in space
While the primary objective was to alter Juice's orbit, the Moon and Earth flybys also provided an opportunity to test Juice's science instruments in space, with all ten turned on during the Moon flyby and eight turned on during the Earth flyby.
Images and spectra collected by JUICE's instruments will be downlinked from the spacecraft, evaluated by instrument scientists and released in the coming weeks, including high-resolution images of the Moon and Earth from JUICE's science cameras. Janus.
“The timing and location of these two flybys will allow us to thoroughly study the operation of JUICE's instruments,” explains Claire Vallat, JUICE's operational scientist.
“Because this happens early on in JUICE's journey, we can use that data to prepare our instruments for its arrival at Jupiter. It's also the perfect place to understand how our instruments will react to real-world targets, given how well we know the physical properties of the Earth, Moon, and the surrounding space environment.”
Next step: Venus
This Moon and Earth flyby actually reduced Juice's energy and redirected it for an encounter with Venus in August 2025. This Venus flyby will propel Juice toward Earth again. The spacecraft will pass Earth again in September 2026 and January 2029, giving it two more boosts before arriving at Jupiter in July 2031.
Juice's Journey to Jupiter: Moon and Earth Flyby
For more information about Juice's Moon-Earth flyby, including why and how it uses a gravity-assisted flyby to reach the inner and outer solar system, see Juice's Moon-Earth Flyby: Everything You Need to Know.
Read more of Juice's Moon and Earth flyby story on the Rocket Science Blog.
to follow Translator For the latest mission updates, see X.
Relive the lunar flyby with ESA's livestream, including a Q&A with mission experts, on ESA's YouTube channel.
About Juice
ESA's Jupiter Icy Moons Explorer, JUICE, is humanity's next bold mission to the outer solar system. It will make detailed observations of the gas giant Jupiter and its three large ocean-bearing moons: Ganymede, Callisto and Europa. This ambitious mission will use a powerful suite of remote sensing, geophysical and in situ instruments to characterize these moons and learn more about these enticing destinations as potential habitats for past or present life.
Jouss will closely monitor Jupiter's complex magnetic, radiation and plasma environment and its interactions with its moons, studying the Jovian system as a prototype for gas giant planet systems throughout the universe.
JUICE is set to launch on an Ariane 5 from Europe's Kourou spaceport in April 2023. During its eight-year voyage, it will flyby Earth and Venus before zipping to Jupiter, where it will make 35 flybys of Jupiter's three largest moons before shifting course to Ganymede.
Juice is a mission led by ESA in collaboration with NASA, JAXA and the Israel Space Agency. It is the first major mission under ESA's Cosmic Vision programme.
For further information please contact ESA Media Relations:
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