ESA - JUICE updates

[matthewkantar]

Paper on deployment glitch and fix: https://www.esmats.eu/esmatspapers/pastpapers/pdfs/2023/leletty.pdf

[deadman1204]

Planetary Society did an interview with Bob Pappalardo, and he mentioned a couple interesting tidbits about juice:

https://www.planetary.org/planetary-radio/2024-europa-clipper-blasts-off

1. The mosfit problem with clipper probably affects juice too
2. the projects hope to coordinate some flybies. He spoke about one where juice will be inside Ganymede's magnetic field while clipper is inside Jupiters. So they'll be able to identify juipter field activity to better interpret juice's measurements of ganymede's field activity.

[flatpf]

1. The mosfit problem with clipper probably affects juice too

Quite frankly, I don't know if ESA was even using the same parts. The mosfets on EC were made to DoD specifications, so my guess would be that they would not be exported from the US, but who knows.

I remember reading that the mosfets ESA tested at Cern were not made by Infineon but STMicroelectronics. From which vendor they ultimately procured their mosfets and what components all the instruments (especially the parts made in the US) use and what batch or plant they came from if they came from Infineon I don't know.

[ugordan]

Even if the MOSFETs suffer from the same vulnerability, JUICE won't be spending as much time deep in Jupiter's radiation belts as Clipper will so it's not as big of an issue for them. Granted, AIUI, Ganymede is still being fairly irradiated, but it's nowhere near as bad as the vicinity of Europa. Probably the only Galilean moon that's outside of the brunt of the belts is Callisto, and, coincidentally seems to be the most ancient and uninteresting of the four (don't fite me).

[StraumliBlight]

ESA Operations Linkedin [Jan 21]

🛜 #Juice: Why… is… the… data… rate… so… low? 
 
Since the beginning of the year, the downlink rate of Juice has been dropping dramatically to only 1/6th of usual data rate.
 
The data rate is currently around 86 kbit/s and in a couple of weeks will be at 43 kbit/s - the same rate Juice will have at Jupiter. By the end of the year, it will as low as 10 kbit/s - which is 10000 times less than the average data rate on mobile phone!
 
So why are we reaching such low rates?
 
1️⃣ The distance to Earth increasing fast with the spacecraft rapidly moving to the other side of the Sun.
2️⃣ The spacecraft has been relying only on its medium-gain antenna for communications, while the main antenna is acting as a heat shield against the Sun.
 
"Since last October and the beginning of the very hot cruise phase, Juice has been constantly pointing its large high-gain antenna toward the Sun to protect the spacecraft," explains Angela Dietz, Juice Spacecraft Operations Manager at #ESOC.
 
"From January 2026, once we are farther from the Sun, we will switch back to the high-gain antenna and put it into operation for the first time. From then on, the data rate will be much more comfortable."

[jacqmans]

Juice team resolves anomaly on approach to Venus
25/08/2025


The European Space Agency’s Jupiter Icy Moons Explorer (Juice) is on track for its gravity-assist flyby at Venus on 31 August, following the successful resolution of a spacecraft communication anomaly that temporarily severed contact with Earth.

The issue, which emerged during a routine ground station pass on 16 July, temporarily disrupted Juice’s ability to transmit information about its health and status (telemetry).

Thanks to swift and coordinated action by the teams at ESA’s European Space Operations Centre (ESOC) in Darmstadt, Germany, and Juice’s manufacturer, Airbus, communication was restored in time to prepare for the upcoming planetary encounter.

Juice falls silent
The anomaly began when ESA’s deep space antenna in Cebreros, Spain, failed to establish contact with Juice at the expected time of 04:50 CEST on 16 July. Initial checks ruled out ground station issues, prompting escalation to the Juice control team at ESOC. Attempts to reach the spacecraft via ESA’s New Norcia station also failed, confirming that the problem was on board.

With no signal and no telemetry, engineers feared Juice might have entered survival mode – a last-resort configuration that is triggered by multiple onboard system failures. In such a state, the spacecraft spins slowly, sweeping its antenna across Earth once per hour. However, no such intermittent signal was detected.

“Losing contact with a spacecraft is one of the most serious scenarios we can face,” said Angela Dietz, Juice Spacecraft Operations Manager. “With no telemetry, it is much more difficult to diagnose and resolve the root cause of an issue.”

Attention turned to the communications subsystem. Engineers suspected either a misalignment of Juice’s medium-gain antenna or a failure in the signal transmitter or amplifier.

https://www.esa.int/Enabling_Support/Operations/Juice_team_resolves_anomaly_on_approach_to_Venus#msdynmkt_trackingcontext=e9a8a7e7-d6f2-44a5-85b0-210d58d90300

[Svetoslav]

It's quite interesting that the European taxpayers weren't informed in a timely manner about the anomaly...

[flatpf]

It's quite interesting that the European taxpayers weren't informed in a timely manner about the anomaly...

Pretty standard ESA information policy. You barely hear about problems, even less about problems that were solved pretty quickly. The mix of different responsibilities for ESA, contractors and instrument providers doesn't help either.

[LouScheffer]

It's quite interesting that the European taxpayers weren't informed in a timely manner about the anomaly...

Seems usual for un-crewed missions.  JPL lost contact with Voyager 1 on 14 November 2023.  There was no mention of this until 12 December, almost a month later.

A month to report on such an issue seems reasonable to me.   Problems happen all the time.  It makes sense to try to fix it first, before making a public announcement.  Anyway, what can the public do?
* Argue that more resources should be allotted to fixing the problem?  Not likely to help, everyone with any hope of contributing is doing so already.
* Argue these turkeys should get less funding as they keep screwing up?  This would only be a concern if the blackout covered a budget cycle decision point.  As far as I know it did not.

A one month delay seems like a reasonable compromise between crying wolf over minor, easily fixed bugs, and letting the public know if there is a serious problem.

[ddspaceman]

ESA Operations
@esaoperations

Reminder that @ESA_JUICE flies past Venus this weekend. The spacecraft was designed to feel at home in the cold, dark environment of the Jupiter system, and it is too hot at Venus to turn the cameras on. Pics or it didn’t happen? You’ll have to trust us on this one.

https://twitter.com/esaoperations/status/1961371308190581006

[flatpf]

ESA Operations
@esaoperations

Reminder that @ESA_JUICE flies past Venus this weekend. The spacecraft was designed to feel at home in the cold, dark environment of the Jupiter system, and it is too hot at Venus to turn the cameras on. Pics or it didn’t happen? You’ll have to trust us on this one.

It's a shame the instruments won't be turned on. The submillimetre spectrometer would show if there is phosphine or not.

[flatpf]

ESA Operations
@esaoperations

Flyby success! @ESA_JUICE passed Venus at 07:28 CEST on 31 August.
..

https://twitter.com/esaoperations/status/1962449913628787036

[StraumliBlight]

https://twitter.com/esascience/status/1977998573066223936

@ESA_Juice reached 30% of its journey to Jupiter! 🙌

[...]

Given Juice is still close to the Sun, it's using its main high-gain antenna as a heat shield. It will be sending data back to Earth using its smaller medium-gain antenna.

It is also far from Earth, on the other side of the Sun. For all these reasons, we don’t expect to receive Juice’s observations of 3I/ATLAS until February 2026. It is a long wait indeed, but it's a big space out there.

[bolun]

JUICE and 3I/ATLAS: An Unexpected Encounter in Space (MPS)

Over the next few days and weeks, ESA's spacecraft JUICE will have a good view of the recently discovered interstellar object 3I/ATLAS.

The JUICE instruments that will be looking at 3I/ATLAS will be operating between November 2 and 25. From an operational point of view, the campaign is tricky. Probe and interstellar object are traveling in different directions, with 3I/ATLAS tearing through space at a speed of approximately 220,000 kilometers per hour. In addition, JUICE can only look directly at its target for no more than 30 minutes per day as to avoid exposing its sensitive side to too much solar radiation. Only PEP, with its significantly larger field of view, can measure for twelve days at a time despite the spacecraft slewing.

Whether JUICE’s efforts were successful will only become clear in February next year. Only then will the observational data be transmitted to Earth – a kind of delayed souvenir photo of a unique encounter.