JUICE, ESA's L-class mission to the Jovian system Options

[machi]

Yellow book is available (13.1.2012) - JUICE.

[antoniseb]

Thanks, that's cool. I hope they can get approval and stay on time. 2022 isn't that far away in the scheme of things.

[Bjorn Jonsson]

Thanks - I finally took a look at this and it is obvious that this would be an extremely interesting mission. A 'Galileo 2' (with the omission of Io though) in a way but with modern and far better instruments (and antenna!). I also get the impression that it would very nicely complement a possible NASA Europa mission since that mission now seems likely to focus almost exclusively on Europa while JUICE is more of a Jupiter System mission - it even includes nice coverage of Jupiter's polar region.

[Seryddwr]

Wasn't a final decision about JUICE supposed to have been made yesterday? I hope they picked it...

[Paolo]

rumors say that JUICE has been recommended for adoption as ESA's next large mission. nothing official so far...
great news if true!

[machi]

It looks official enough (at least for me).

ESA/SPC(2012)12

[Bjorn Jonsson]

This is great news. Detailed information is available and from what I've read this mission is vastly superior to Galileo (even if its HGA had worked), thanks to modern instruments etc. (a difference of at least 30 years). In a way this is Jupiter's 'Cassini' - not as big but with more modern instruments.

[tasp]

The link mentions an ice penetrating radar.


I am agog with the possibilities. They also discuss the radiation requirements and seem confident the cumulative dose will be survivable.

[machi]

I have another informations about L missions.
JUICE was recommended by SSAC and SSEWG groups, ATHENA by AWG group and NGO by PSWG group.
JUICE is preferred choice, but it isn't still 100% certain. Final (formal) decision by ESA members is expected on 2 May.

[Drkskywxlt]

Fantastic news! I've very impressed by the high data rate (1.4Gbit/day) and the ability to operate 11 instruments on solar power at 5AU. Also glad to see that they are not at all relying on NASA or JAXA support for the mission, although I hope those agencies can support the mission in some way.

[Paolo]

I was split between JUICE and LISA, but LISA or NGO or whatever it is called now would have been my favorite choice, for the Nobel prize science it would produce and for the technological challenges it implied, but still I'm quite happy with JUICE!

[vjkane]

You can read the current presentation summarizing the mission from the proposal team at http://www.lpi.usra.edu/opag/mar2012/prese...ICE_Summary.pdf

[djellison]

Looks to me like they're planning something around 350-400 kbps - which would be spectacular from Jupiter. Can't find a data rate directly, but can infer it from the 1.4Gb in an 8hr pass.

[Seryddwr]

Obviously, I think everybody here would have preferred it if ALL the missions were commissioned!

But if it is JUICE that's been picked, it sounds tremendous. Something to look forward to in a few years. Plus it will be good to finally get global coverage of Europa instead of the pinpricks of data that came from Galileo. Reading the Atlas of the Galilean Satellites is a rewarding but frustrating experience - like hearing a few seconds of Beethoven's Ninth or seeing a couple of square feet of Guernica...

[john_s]

No global Europa coverage from JUICE, except at low resolution- there are only two Europa flybys, both at similar longitudes. Still, with high data rates and an ice penetrating radar, these should provide a spectacular improvement in our understanding.

John

[stevesliva]

Something to look forward to in a few years.

Eighteen years (!)

But I should say-- I'm still excited nonetheless!

[Guest_Sunspot_*]

Arrival date 2030

[Drkskywxlt]

Earth-Venus-Earth-Earth gravity assists. Tradeoff for having a big spacecraft with relatively moderate onboard delta-V capability.

[Bjorn Jonsson]

Impressive imaging capabilities (from the yellow book mentioned in the first message of this thread):

A narrow angle framing camera with 1024x1024 pixels, 0.3° FOV and 12 filters that can also do pushbroom imaging. This is roughly two times Galileo's resolution (800x800 and 0.47°) and means that e.g. Io monitoring is possible in addition to Jupiter and icy satellite imaging. For comparison, Cassini's NAC has a FOV of 0.35° and 1024x1024 pixels.

A wide angle camera with 1024x1024 pixels, 117° FOV and 12 filters.

A hyperspectral pushbroom imager with 3.4° FOV, 0.4-5.2 μm spectral range and spectral sampling 2.8-5.0 nm, lines x arrays=640 x 480.

These specs are apparently not final though.

[machi]

I did some quick comparison, what could be seen from JUICE, based on informations in Yellow book.

Image resolution comparison between older missions and JUICE's NAC camera:


And images of different bodies in Jovian system at resolutions obtainable by same camera:



Some more informations are on my blog.

[Bjorn Jonsson]

Another hurdle has been crossed - JUICE was approved unanimously by the ESA member state delegations today. News here:

http://www.bbc.co.uk/news/science-environment-17917102

Great news - on to Jupiter!

[machi]

Same news from ESA.

[belleraphon1]

I LOVE outer planet missions.

JUICE Spacecraft gets to Jupiter in 2030… I will be 77 that year and my grandsons will be 24. In the span of my life I will have seen PIONEERS, VOYAGERS, GALILEO, ULYSSES, CASSINI, NEW HORIZONS, JUNO (maybe a new Europa/ Titan/ Enceladus) encounters with Jupiter, Saturn, Uranus, Neptune, Pluto, and perhaps some Kuiper Belt objects. Ironically by 2030 we may have sensed the air of terrestrial type exoplanets. But physical travel to the bodies in our own solar system is still at a snail’s pace and outer planet missions (given chemical and low power electric propulsion) are still events for a generation. SIGH!

[TheAnt]

Yes the flight time with those gravity assists are considerable, and that even when launched by one Ariane 5.
Now that Ariane 5 ME will be available with the new upper stage, a shorter flight time might be available at the time for launch.

Yet of the about 5 ton to be sent to Jupiter, up to 3 tons might have to be propellant, some substantial part of that to be "juiced" for going into orbit around Ganymede.
And even though quite some of you appear to be pining for Europa, it is one really interesting moon, a magnetic field and where the grooved terrain is a sign of ice tectonics. And perhaps one liquid interior also, though not from current tidal heating so either from internal heat or preserved from the past when the interaction with Io and Europa were stronger, (the eccentricity is very low right now, but it might vary over quite long timescales - a possible connection to the magnetic field there, and Ganymede might even have auroras!)
Now with such a name they might have a perfect opportunity to get a sponsor, though it might be at the risk of getting the suggestion to have the space probe painted orange. *Ducks*

[belleraphon1]

I'd be ok with orange but not sure what that would do to the spacecraft's thermal properties.

Agree that Ganymede is indeed worthy of this visit. As is Callisto. All the Galilean moons are exciting worlds in their own right.

Craig

[Paolo]

I am amazed by how much solar panel technology has progressed in the last 30 years... Galileo had two RTG delivering 570 W at launch and 485 W at end of mission, JUICE will have solar panels delivering up to 636 W at end of mission. wow!

[tusenfem]

Ah! Instrument selection this month!
Let's see if the two instrument packages that I am involved in get selected.

January 2013 SSEWG and SSAC recommendations
February 2013 Preliminary technical KO of instrument Phase A
February 2013 SPC selection

[tasp]

I bet we already have contributors here imagining those 'Kodak moment' shots we all love.

A crescent Jupiter half risen above a craggy Ganymedean ridge with an Io suspended above the nightside perhaps . . .

[rlorenz]

Ah! Instrument selection this month!

http://www.esa.int/Our_Activities/Space_Sc..._moons_explorer

[mcaplinger]

http://www.esa.int/Our_Activities/Space_Sc..._moons_explorer

Anybody know the specific team affiliations? The release doesn't say.

[stevesliva]

Nice list of instruments. Doing all that w/o a scan platform like Cassini?

[Bjorn Jonsson]

That's something that would be interesting to know - turning a spacecraft with big solar arrays is more difficult than turning a spacecraft like Cassini. It would also be extremely interesting to know something about the instrument specs.

[Paolo]

anybody knows the difference between the Gravity & Geophysics of Jupiter and Galilean Moons and the Planetary Radio Interferometer & Doppler experiments?
they look like both radio tracking experiments

[remcook]

For PRIDE it says there is no spacecraft component, just the VLBI, so maybe 3GM is only the spacecraft component?

[bobik]

I do miss a micrometeoroid-experiment. SUDA (SUrface Dust Analyser) not onboard?

[ollopa]

Does anyone know what the Irish involvement is? The ESA press release gives no details and they haven't replied to my query yet.

[pospa]

Not sure about Irish part, but I can provide info about Czech involvement if someone's interested.
Google translation of recent Czech Space Office announcement.

[MarcF]

A Russian Ganymede lander in addition to the European JUICE orbiter ?
http://english.ruvr.ru/2013_03_11/Mission-...-than-expected/
Marc.

[Bjorn Jonsson]

More detailed information on the instruments:

http://sci.esa.int/science-e/www/object/in...fobjectid=50073

In particular, the camera (JANUS) has a field of view of 1.3 degrees and carries 13 filters. This is a bigger field of view than the 0.3 degrees discussed earlier in this thread but the size in pixels is not shown (I'd love to see more detailed information on the camera specs). 2048x2048 wouldn't surprise me and would result in a resolution comparable to the Galileo camera. There's no mention of a wide angle camera and there's no information on whether pushbroom imaging is possible. One good thing about 1.3° vs. 0.3° is that global scale mosaics of Jupiter would have been a problem with a 0.3° FOV (huge number frames).

MAJIS is also a very interesting instrument - a hyperspectral imager from 0.4 to 5.7 microns with a top resolution of ~100 km for Jupiter and 25 m for Ganymede.

[Bjorn Jonsson]

I found some additional information on the imaging experiment (JANUS) here:

http://meetingorganizer.copernicus.org/EPS...PSC2013-506.pdf

Not much new information on the camera itself though. The most interesting thing to me is that it has WAC imaging capabilities in addition to the 1.3° field of view and it's a framing camera. Reading between the lines it seems to me that the image size in pixels is ~2048x2048. This is not explicitly mentioned but the resolution numbers seem to imply something like this.

However, there is considerable information on the planned imaging coverage. In particular, compared to Galileo the coverage of Europa looks impressive to me since there are only two close Europa flybys.

[Bjorn Jonsson]

More detailed information on the JUICE instruments is gradually becoming available. I recently found this interesting PDF document from the 45th LPSC (2014) conference:

http://www.hou.usra.edu/meetings/lpsc2014/pdf/2094.pdf

The most interesting new information to me is a list of the JANUS filters:

[pitcapuozzo]

Airbus has won the 350.8 mln euro contract to build JUICE over Thales Alenia's competition.


http://spacenews.com/airbus-to-build-esas-...-juice-orbiter/

[bobik]

The JUICE project has started the JUICE Test Campaign Journal. Hopefully with many more entries to come, so that it would not become such a stealth project like Solar Orbiter.

[bobik]

The JUICE probe will have two JUICE Monitoring Cameras (JMC) with RGYB pixel arrays. Recently, it was revealed that the JMC would even get a Colour Chart (CC) for true colour reconstruction. Spectacular views guaranteed!

[bobik]

OBTW, ESA has without much ado given up on the June 2022 launch opportunity. JUICE is now scheduled for an August-September 2022 launch, which translates to no Mars flyby (but one Moon-Earth flyby), Jupiter Orbit Insertion some one and a half years, and Ganymede Orbit Insertion two years later than planned for a June 2022 launch.

[bobik]

Taking into account ESA's dumb way to communicate JUICE's launch delay to 2023 and that so far no new official launch date and trajectory has been published, I am wondering if ESA's PR people are trying to tease us with this sort of tweet

[bobik]

Unbelievable! Finally, someone with a Twitter account has got the cojones to ask ESA about the JUICE launch date and has even got a more or less useful reply: "...stay tuned!"

[bobik]

A new JUICE baseline trajectory (CReMA 5.0b23.1) is published - launch on 5 April 2023. Earlier, August 2023 was mentioned as back-up launch date. By the way, is there an easy and convenient way to read or visualize Orbit kernels?

[mcaplinger]

By the way, is there an easy and convenient way to read or visualize Orbit kernels?

You can use SPICE-enhanced Cosmographia https://naif.jpl.nasa.gov/naif/cosmographia.html but I would call that neither easy nor convenient. There's a steep learning curve, especially with setting up the JSON files.

[volcanopele]

At least for ESA Missions there are official Cosmographia add-ons that make adding them pretty simple:

https://www.cosmos.esa.int/web/spice/cosmographia

[Brian Swift]

.. By the way, is there an easy and convenient way to read or visualize Orbit kernels?

A relatively easy way to produce plots and tables is the ESA WebGeocalc web page.
.
The above plot of distance to Jupiter was produced by first selecting "juice_crema_5_0b23_1" kernel set from the pulldown,
and entering the below settings in the GUI.

CODE

Target type    Object
Target    JUPITER
Observer type    Object
Observer    JUICE
Reference frame    IAU_JUPITER
Light propagation    No correction
Time system    UTC
Time format    Calendar date and time
Time range    2023-05-01 to 2031-08-01
Step    200 equal intervals
State representation    Rectangular

Note: The IAU_JUPITER (rotating) Reference Frame isn't isn't a good choice for plotting positions. Using JUPITER_SUN_ORB
(of which I haven't looked up the definition) for the Reference Frame, and plotting the X,Y positions (from downloaded CSV table)
looks like:

[vjkane]

At least for ESA Missions there are official Cosmographia add-ons that make adding them pretty simple:

https://www.cosmos.esa.int/web/spice/cosmographia

For those who can read this data, when does the spacecraft arrive at Jupiter? Thanks.

[vjkane]

At least for ESA Missions there are official Cosmographia add-ons that make adding them pretty simple:

https://www.cosmos.esa.int/web/spice/cosmographia

For those who can read this data, when does the spacecraft arrive at Jupiter? Thanks.

[bobik]

Many thanks! Cosmographia gave me an error message when I tried (not very hard) to load the JSON file, however WebGeocalc works fine for me, with the help of the above example.

If I made no mistake,

Launch: 2023-04-05

Moon : 2024-08-19
Earth : 2024-08-20
Venus : 2025-08-31
Earth : 2026-09-28
Earth : 2029-01-17

JOI : 2031-07-21 (a year earlier than with the August 2023 launch trajectory)

[StargazeInWonder]

It's remarkable – almost comical – that after a quarter century, two missions are going to arrive for overlapping jovian system science at almost the same time. Now it looks like Europa Clipper will make a close pass of Europa before JUICE does but it's like watching a close horse race. And won't really matter; it'll be great to get the complementary science as both make observations with similar but non-identical instruments.

Interestingly, both missions' radar instruments have a mode at 9 MHz, which might make them a little less complementary than redundant in kind. Still, 46 radar tracks is better than 44.

[stevesliva]

Would be nice if the continuing presence continued more places than LEO. At a minimum Mars and Jupiter. But one can easily dream of the rest.

[StargazeInWonder]

The inner jovian system has radiation to prohibit long lifetimes and the outer jovian system would exclude the targets of highest interest.

Future telescopes are going to have amazing resolution of Jupiter from Earth, so monitoring Jupiter from the vicinity of Callisto or farther wouldn't add much value, either.

[Bjorn Jonsson]

Future telescopes are going to have amazing resolution of Jupiter from Earth, so monitoring Jupiter from the vicinity of Callisto or farther wouldn't add much value, either.

It's correct that future telescopes will have amazing resolution. However they will be busy observing many different targets and can observe Jupiter only occasionally (this is also true today for the largest groundbased telescopes). So observations by amateur astronomers (or a spacecraft imaging Jupiter from Callisto's orbit or farther out) are still going to be highly valuable because of their time resolution.

And this is an updated ESA animation showing the JUICE trajectory and the dates of several major mission events:
https://youtu.be/Fw17N3rdN7s

[bobik]

And this is an updated ESA animation showing the JUICE trajectory and the dates of several major mission events:
https://youtu.be/Fw17N3rdN7s

I don't get it, as early as 9 March, ESA has posted a bunch of videos about JUICE's new trajectory on Youtube exclusively (what is questionable) without any press release or slightest hint about it on it's official websites or even JUICE's twitter account, what seems to be presently it's main outreach channel (what is even more questionable). It's certain that ESA's PR - or better said, it's information policy is badly flawed.

[bobik]

Finally the latest (much-anticipated) The Making of JUICE episode has been released.

[bobik]

This asteroid (223) Rosa fly-by opportunity should be still valid, because starting with the Venus swing-by the April 2023 launch trajectory is identical with the September 2022 launch trajectory.

Edit: New paper on the "analysis of possible asteroids flyby for the ESA JUICE mission", albeit behind paywall.

[bobik]

After a month of silence, a JUICE science instrument tweet informs us that "[t]he structural tests of the [JUICE] spacecraft are finished as well as the reduced functional tests afterwards. GALA and all other instruments are nominal." -- ESA's public outreach is so broken!

Edit (2022-07-19): Oh now, JUICE's contractor tweets a short (58 sec) video about the completed vibration and acoustic tests.

[bobik]

Juicy news from French Guiana on the launch preparation of JUICE on a controversial social-media website, although I think that it would be far easier, and a better idea to simply publish the JUICE launch campaign newsletter, as fortunately the Russian MGNS scientists did during the BepiColombo launch campaign in 2018.

[nogal]

It is easy to search the ESA website... Trying https://www.esa.int/esearch?q=JUICE yelds many, many entries.
Here is one of the latest

https://www.esa.int/Enabling_Support/Space_...unch_to_Jupiter
Fernando
PS - or subscribe the news topic. Cheers

[bobik]

It is easy to search the ESA website...

If you could only find the weekly (or so) JUICE Launch Campaign Newsletter, this would be big news.

[bobik]

JUICE: All instruments are GO

[nprev]

After all these years launch day has arrived!!! T-0 scheduled for 1215 GMT.

Watch live here: https://youtube.com/watch?v=ZD9n9HLwswQ

More info: https://www.esa.int/.../How_to_foll...ice_launch_live

GO JUICE!!!

[john_s]

Sigh- not today. Scrubbed due to lightning risk. Will try again tomorrow, one minute earlier.

John

[Bjorn Jonsson]

So far so good. I have probably not been this excited about a planetary spacecraft launch since 1997 (Cassini).

[nprev]

Spacecraft separation and JUICE is on its way!

[Bjorn Jonsson]

Both solar arrays fully deployed, a major milestone.

[StargazeInWonder]

Great news!

Bjorn's mention of 1997 helps me frame how I, and I'm sure some others see this: Since the Galileo Orbiter, that mission's shortcomings, notably the extremely limited data rate, have created the feeling that we needed a follow-up to replace the thorough study of the Galileans that we lost. Now, though it will arrive 35 years (!) after Galileo did, this is going to be a major part of filling that gap. Combined with Europa Clipper, JUICE will far more than replace the observations we lost back in 1996-2000 as far as the three outer Galileans go.

But for now, we wait some more!

[MarcF]

I remember, back in 2007 I first posted here about a possible ESA/NASA collaboration to send several probes to explore further the Jovian system. At that time the project was called Laplace.
http://www.unmannedspaceflight.com/index.php?showtopic=4637
Most of reactions were pessimistic (if not sarcastic).
A lot happened since and there were many changes, but finally JUICE is on its way to the Jovian system and Europa Clipper will follow soon.
These will be 2 amazing missions.

[StargazeInWonder]

Thanks for linking to the history, Marc.

While some ambitions have been postponed, the combination of Juno, JUICE, and Europa Clipper will put us one Io mission away from an excellent survey of the jovian system, at last, and ESA is on the way to doing their part.

[Bjorn Jonsson]

That was quick - images from the Juice Monitoring Cameras (JMC) have already been released. Juice's first 'selfies': https://www.esa.int/Science_Exploration/Spa...fies_from_space

[volcanopele]

Hopefully these cameras stick around until the tour. They make great public relations cameras since they help to provide a “you are there” perspective which the science camera can sometimes lack do the narrow field of view.

[rlorenz]

I remember, back in 2007 I first posted here about a possible ESA/NASA collaboration to send several probes to explore further the Jovian system. At that time the project was called Laplace.
A lot happened since and there were many changes, but finally JUICE is on its way to the Jovian system and Europa Clipper will follow soon.

Indeed. There were NASA-funded ($1M each, IIRC) Flagship studies in 2007, one to Europa, one to Ganymede/Jovian System that were in parallel with (and actually had more technical analysis than) the Laplace concept (just a community response to an ESA call for ideas). At the same time, there was an ESA idea called TandEM and NASA Flagship studies for Titan, and for Enceladus - I served as project scientist and Science Definition Team chair for the Titan one : we came up with a single-launch lander + balloon + aerocapture concept.

In 2008, these studies were consolidated into a next joint study phase - Europa Jupiter system Mission (EJSM), and Titan Saturn System Mission (TSSM). NASA directed that TSSM must do both Titan and Enceladus, could not use aerocapture (negating a major advantage of Titan as a target), and that ESA would supply the sexy bits - lake lander and balloon. Unsurprisingly, although a credible mission design emerged, NASA elected to pursue the Europa mission (which eventually, via much convolution, became Clipper) to complement ESA's JUICE mission. (The 2013 Decadal Survey had a Ganymede New Frontiers mission, but basically said 'its a great mission, but ESA will probably do it...)

After a hopeful digression to explore a low-cost Discovery concept (the Titan Mare Explorer in 2012, thwarted by a stalled NASA radioisotope Stirling generator development, leaving NASA no choice but to select InSight instead) Titan was left out in the cold for the 20-teens.

But then in 2016, when NASA added Titan/Enceladus to the New Frontiers target list, Dragonfly was conceived, and was able to draw on the combined objectives that had been defined for a Titan lander and a Titan balloon back in 2007......

It's funny how things turn out.

[bobik]

According to this timeline, the RIME antenna should already be deployed. Unfortunately, ESA has largely fallen dumb, since the fine launch coverage, so who knows what's going on.

[bobik]

12 days after launch, ESA still continues to hold on tightly to its JUICE information embargo, however, in the Planetary Science Archive (PSA) has recently appeared a bunch of JUICE Monitoring Camera (JMC) images, albeit still 'On Hold'. A large quantity of images were made on 2023-04-19, probably the day of the RIME antenna deployment. At the meantime the magnetometer boom should also already be deployed, according to this pre-launch timeline.

PS. RADiation-hard Electron Monitor (RADEM) and High Accuracy Accelerometer (HAA) data are also flowing into the PSA.

[Bjorn Jonsson]

The magnetometer boom has been deployed: https://www.esa.int/ESA_Multimedia/Images/2...ence_from_space

[bobik]

Magnetometer boom deployment on 2023-04-21 at 14:29:38 UT, early on the 8th day of the expedition, so the published pre-launch timeline isn't very valid. Successful deployment has been made public five days after the event, strikingly, the web release doesn't mention the deployment of the RIME antenna, although successful deployment of the solar arrays and the medium gain antenna (MGA) is mentioned, thus RIME antenna status so far unknown.

[climber]

RIME didn’t fully deployed : https://www.esa.int/Science_Exploration/Spa...ce_RIME_antenna

[dtolman]

Is RIME all or nothing? If it ends stuck at 1/3 deployed, is it still somewhat usable?

[StargazeInWonder]

The sun-shadow approach to unstick the problem would seem to be most effective, potentially, when JUICE is closest to the Sun, which will be six months from now around the time of its Venus flyby. So I guess that the time for greater worry would be if it remains stuck after that opportunity.

Partial deployment would certainly impact resolution at the very least, but whether or not partial deployment would permit useful operation depends upon further details which don't seem to be available yet. How much of the antenna is now perpendicular to the instrument's "look" direction; how much noise would be returned from the remaining portions of it? Hopefully we won't have to face those questions. If worse comes to worst, it remains true that Europa Clipper will also provide the opportunity to study Europa thorough with similar capability, and some representative ground tracks at Ganymede and Callisto.

[bobik]

RIME didn’t fully deployed : https://www.esa.int/Science_Exploration/Spa...ce_RIME_antenna

According to the large quantity of JMC images in the PSA, they already tried something to release the antenna on 2023-04-27, however, which apparently didn't work.

EDIT: I don't think there is a description of the RIME Hold-Down and Release Mechanism (HDRM) published, at least I can't find one, but there are some photos on the web. Hmm... so where lies the problem?

[Bjorn Jonsson]

RIME antenna successfully deployed!!

https://www.esa.int/Science_Exploration/Spa...nna_breaks_free

[nogal]

Good news. The RIME antenna is free

See ESA announcement at https://www.esa.int/Science_Exploration/Spa...nna_breaks_free

PS: well done Bjorn! I was fiddling with the mobile's keybord and did not notice your post

[Explorer1]

Bravo! May that pin never be seen again!
(And the advantage of having engineering cameras is demonstrated once more...)

[climber]

They deserve Champagne, not only free juice 🤦‍♂️

[StargazeInWonder]

If you count Lucy's solar panels, and Juno's valves, all four orbiters that have been sent to Jupiter (and its Trojans) have had a part stuck during deployment. Luckily, all of these have had successful workarounds and a complete resolution in this case, but that four out of four number is eyebrow-raising.

[djellison]

that four out of four number is eyebrow-raising.

Why?

There isn't a spacecraft out there that hasn't had a failure with workarounds. These things are incomprehensibly complicated. Thousands of components.

Cassini had a reaction wheel go out super early. SOHO was nearly lost 20 years ago. Galileo's HGA. MGS's solar panels. MEX concerns over MARSIS deployment, MRO Ka band going down etc...etc...etc.

They all have their problems. And their teams work around it.

[StargazeInWonder]

I think you may have read a criticism in my comment that I didn't intend. Of course very complicated projects have problems that are often possible to overcome.

In this case, the similarity of the problems and the same target simply seemed curious. Lots of missions have lots of different issues, but here three had issues with something external failing to extend correctly, and all with the same target. It's certainly not pejorative regarding the teams, and as the problems with Galileo, Lucy, and JUICE all occurred so long before arrival at Jupiter, there's no casual relationship there.

It's also four different teams, two agencies, different decades… obviously no one pointing the blame at anyone.

[djellison]

It just seemed an odd comment to make - it appeared you were trying to infer there was something about the target that had something to do with the issues.

[StargazeInWonder]

Understood. No, the fact that these have happened so far from Jupiter makes that definitely coincidental. If they'd all happened in Jupiter's radiation belts, that'd be another thing.

Likewise, the Soviets had rotten luck with Mars missions, but some of them occurred at/near launch. Mars didn't cause that, but the mishaps randomly piled up that way. So it goes.

[tanjent]

Jupiter is the most distant target planet for which probes can manage on solar power without RTG's. So spacecraft going there need big panels, intricately folded prior to launch. Likewise I am guessing that the communications antennae need to be larger relative to the spacecraft itself than for probes heading to the inner planets and Mars. So the engineering challenges involved in powering and communicating with Jupiter-bound payloads are bound to be daunting.

[HSchirmer]

Jupiter is the most distant target planet for which probes can manage on solar power without RTG's. So spacecraft going there need big panels, intricately folded prior to launch. Likewise I am guessing that the communications antennae need to be larger relative to the spacecraft itself than for probes heading to the inner planets and Mars. So the engineering challenges involved in powering and communicating with Jupiter-bound payloads are bound to be daunting.

And it certainly doesn't help that, for a Jupiter-bound mission, you're on a heavy lift rocket.
So your delicate science probe that's assembled in a clean room and likely barely be able to support its own weight in earth gravity-
will spend several minutes being shaken within an inch of its life (specifications?) and blasted by 150+ decibels of sound energy.

As well as go from 1 atmosphere to hard vacuum in a matter of minutes and then from ~85° Fahrenheit to a rotisserie of +250°F and -150°F.

[vjkane]

Jupiter is the most distant target planet for which probes can manage on solar power without RTG's. So spacecraft going there need big panels, intricately folded prior to launch. Likewise I am guessing that the communications antennae need to be larger relative to the spacecraft itself than for probes heading to the inner planets and Mars. So the engineering challenges involved in powering and communicating with Jupiter-bound payloads are bound to be daunting.

There have been several proposed solar powered Discovery and New Frontiers-class missions for the Saturnian system across 2-3 competitions. I've never heard that the reasons they weren't chosen was because of the proposed use of solar power. Two of the losing teams gave debriefs on the reviews of their proposals at an OPAG meeting, and solar power wasn't mentioned.

Given how small this community is, if solar power wasn't going to get past reviewers (and the reviews assess technical feasibility), I think that would be known by now in the community. The recent Decadal Survey Enceladus multiflyby concept used RTG, and they note was that RTGs were more mass efficient.

I don't think that we can say for certain about solar power at Saturn until a mission is selected, but there are good examples of professionals in the field believing they can will mission concepts using solar power.

BTW, NASA is offering up to two MMRTGs for the upcoming NF5 competition. Missions have been proposed to each of the candidate destinations using solar power. If the winning mission does use solar power, the fuel could be repackaged into a next get RTG and offered to a Uranus mission. (Repackage for more efficient and long lived thermocouples than MMRTGs.) This would give the mission about a third of what's been desired in most Uranus flagship orbiter concept designs, or about enough for a NF-class orbiter. The alternative, per the recent OPAG meeting is to miss the early 2030s window and wait until the mid or late 2030s and much long flight times.


Space News: Plutonium availability constrains plans for future planetary missions

[stevesliva]

If we're talking Jupiter orbiter coincidences, I'd like to request a Shoemaker-Levy comet impact. TIA!

[MahFL]

Trying to be neutral on the subject, you'd think by now mechanical engineering could design some 99.999% reliable release mechanisms...

[djellison]

What does it tell you about the scope and scale of the design problems and the challenges these unique environments present that - across different agencies, different contractors and both public and private sector projects.........problems of this kind emerge from time to time.

Fascinating reading here - https://ntrs.nasa.gov/api/citations/2021002...nal%20Paper.pdf