This week on Aug 19-20, ESA’s Jupiter Icy Moons Explorer (Juice) will perform the first-ever lunar-Earth double flyby and gravity assist maneuver.
It is the first of 4 gravity assist maneuvers before the spacecraft heads out for arrival at Jupiter in 2031.
Moon flyby: Mon Aug 19, 21:16 UTC, 700 km alt
Earth flyby: Tue Aug 20, 21:57 UTC, 6,807 km alt
The delicate maneuver will slow down Juice, so that it can reach Venus for the next flyby/slingshot in Aug 2025.
It is easier to understand how the trajectory of the Juice spacecraft will change after the double flyby of the moon and earth this week from the following Sun-centric orbital diagrams.
The maneuver will slow down Juice, causing it to head towards the orbit of Venus, where it will accelerate and get a gravity assisted speed boost in Aug 2025.
The L-shaped trajectory of Juice shown in post #1 is Earth-centric.
https://eyes.nasa.gov/apps/solar-system/#/sc_juice?time=2024-06-01T17:44:59.000+00:00
#Juice #EsaJuice
For ESA’s Jupiter Icy Moons Explorer (Juice), this week's lunar-Earth double flyby is the first of 4 gravity assist maneuvers before the spacecraft heads out for arrival at Jupiter in 2031.
Apr 2023 Launch
Aug 2024 Lunar-Earth flyby #1
Aug 2025 Venus flyby
Sep 2026 Earth flyby #2
Jan 2029 Earth flyby #3
Jul 2031 Jupiter orbit insertion
This 8-year trajectory to Jupiter with multiple gravity assist flybys requires lot less fuel than a direct flight to Jupiter.
https://www.esa.int/ESA_Multimedia/Images/2024/07/Juice_s_journey_to_Jupiter_the_lunar-Earth_flyby
3/n
This is the first-ever double lunar-earth gravity assist. For Juice, the alignment of the moon and earth offered an attempt to do this tricky and risky maneuver.
Gravity assist flybys require very precise approach trajectory and speed. After the flyby, errors in the path are measured and corrected. In the lunar-earth flyby, there is less than 24 hours to make such corrections. Advances in ground systems and software make this flyby possible.
🤞
https://www.youtube.com/watch?v=e5zUG7cfkq8
https://blogs.esa.int/rocketscience/2024/08/07/why-has-no-one-attempted-a-lunar-earth-flyby-before/
4/n
At closest approach to earth on Aug 20, 21:57 UTC, Juice will not be easily seen by amateur observers.
Juice will be located over the northern part of the Pacific Ocean. It will be daytime in the area. Juice will be moving at over 30,000 km/h relative to earth.
https://eyes.nasa.gov/apps/solar-system/#/sc_juice?rate=0&time=2024-08-20T21:57:14.000+00:00
#Juice #EsaJuice
5/n
The Juice spacecraft is now being continuously tracked by Estrack, ESA's global ground station network.
Currently, the ground station at Malargüe, Argentina is tracking Juice. Current distance to Juice = 599,584 km.
http://estracknow.esa.int/#/2024-08;mission=JUIC
https://www.esa.int/Enabling_Support/Operations/ESA_Ground_Stations/Estrack_ESA_s_global_ground_station_network
#Juice #Estrack
6/n
For more info on the ESA Jupiter Icy Moons Explorer (Juice) mission and spacecraft, check out these earlier threads -
https://fosstodon.org/@AkaSci/110441199890065297
https://fosstodon.org/@AkaSci/110356844140699352
https://fosstodon.org/@AkaSci/110310144702333395
https://fosstodon.org/@AkaSci/110203000520961762
https://fosstodon.org/@AkaSci/110196855592852020
https://fosstodon.org/@AkaSci/110191010048015933
https://fosstodon.org/@AkaSci/110188634391154003
https://fosstodon.org/@AkaSci/110180175286731281
Attached: 1 image The various antennas, probes and booms are now fully deployed on the ESA Jupiter Icy Moons Explorer (JUICE) spacecraft, 6 weeks after launch. This week, the 4 Langmuir Probes and 3 antennas of the Radio & Plasma Wave Investigation (RPWI) were successfully deployed. Most instruments have been checked out, including the JANUS camera/imager which took a sequence of 7 test images of a star field centered around eta Cyg in the Cygnus constellation. https://www.esa.int/Science_Exploration/Space_Science/Juice/Juice_deployments_complete_final_form_for_Jupiter #ESA #ESAjuice 1/n
ESA will host a 30-minute livestream from its European Space Operations Centre (ESOC) in Darmstadt, Germany, at 21:30 UTC tonight.
The livestream will begin shortly after Juice has passed its closest point to the Moon, after which Juice will send 1kx1k bw images from its monitoring camera.
Images will be downlinked to the Cebreros deep space communication station in Spain and forwarded to ESOC in Germany for processing.
https://www.youtube.com/watch?v=ZoodtR-46Ms
More info at https://blogs.esa.int/rocketscience/2024/08/19/join-us-live-as-juice-flies-past-the-moon/
#Juice
8/n
First image from Juice as shown in the livestream by ESA.
It is an image of the star field, taken just before the spacecraft went behind the moon minutes ago. Contains a few faint distant stars.
9/n
Here are 2 color images taken by the monitoring camera onboard ESA Juice during yesterday's lunar flyby.
Note that this low-res camera is used for spacecraft monitoring purposes. Juice carries a more sophisticated telescopic camera JANUS for imaging Jupiter and its moons.
JANUS = Jovis, Amorum ac Natorum Undique Scrutator, Latin for "comprehensive observation of Jupiter, his love affairs and descendants." 😀
Earth flyby later today at 21:57 UTC.
https://blogs.esa.int/rocketscience/2024/08/20/juice-admires-moon-during-lunar-flyby/
#Juice #EsaJuice
10/n
Good news - yesterday's lunar flyby and gravity assist maneuver by the ESA Juice spacecraft went flawlessly. The Flight Dynamics team states that no trajectory fine-tuning or correction is needed before tonight's Earth flyby.
That's quite a feat!
We presume they have also cross-checked for any earth-orbiting satellites and space debris in Juice's path.
Earth flyby later tonight at 21:57 UTC. There probably will be a livestream on YouTube like yesterday.
Looks like the ESA Juice spacecraft will not send any images tonight after the earth flyby and gravity assist maneuver.
The ESA Operations team states that Earth's thermal radiation is causing the spacecraft electronics to heat up. Hence, although Juice will continue to gather data and capture images, it won't transmit any more data to Earth until 04:16 UTC (00:16 ET) tomorrow morning.
The earth flyby of the ESA Juice spacecraft went flawlessly last night. Juice is now on its way to the Venus flyby in Aug 2025.
The flyby of the Moon increased Juice’s speed by 0.9 km/s relative to the Sun, guiding Juice towards Earth. The flyby of Earth (6,840 km alt) reduced Juice’s speed by 4.8 km/s, guiding Juice onto a new trajectory towards Venus.
The maneuver saved the mission ~100–150 kg of fuel.
Here are some pics taken by the monitoring cameras.
https://www.esa.int/Science_Exploration/Space_Science/Juice/Juice_rerouted_to_Venus_in_world_s_first_lunar-Earth_flyby
#Juice
13/n
Note that taking pictures was not a mission objective of this flyby.
But these flybys provide an opportunity to test out the cameras and other instruments, most of which will wait another 7 years before their mission starts.
All 10 instruments were active during the Moon flyby, 8 during the Earth flyby.
The science camera JANUS also took some pics.
Juice has 2 monitoring cameras. The table below has guessed specs and comparison with JANUS and JunoCam.
AkaSci 🛰️
Veza85UE
#Pfleger aus #Münster🏳️🌈🇪🇺🌈🌻