[HN Gopher] ESA's Juice lifts off on quest to discover secrets o...
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ESA's Juice lifts off on quest to discover secrets of Jupiter's icy
moons
Author : Tevias
Score : 108 points
Date : 2023-04-14 20:17 UTC (2 hours ago)
(HTM) web link (www.esa.int)
(TXT) w3m dump (www.esa.int)
| [deleted]
| rufus_foreman wrote:
| I guess plume flybys technically don't count as attempting a
| landing?
| t3estabc wrote:
| [dead]
| macintux wrote:
| Previous discussions over the last two days:
|
| * https://news.ycombinator.com/item?id=35568388
|
| * https://news.ycombinator.com/item?id=35551870
| dang wrote:
| Thanks! Macroexpanded:
|
| _Juice launch to Jupiter - Live [video]_ -
| https://news.ycombinator.com/item?id=35568388 - April 2023 (29
| comments)
|
| _ESA - Jupiter Icy Moons Explorer: Live Launch_ -
| https://news.ycombinator.com/item?id=35551870 - April 2023 (70
| comments)
| drewg123 wrote:
| Wow, 11 years to Jupiter. I wish we had better propulsion
| systems.
|
| EDIT: This wasn't meant to disrespect the ESA mission. I'm just
| sad that the outer planets are years away, rather than the hours,
| days, weeks or months of science fiction.
| huhtenberg wrote:
| 8 years, not 11.
|
| > _Arrival at Jupiter - July 2031_
|
| https://www.esa.int/var/esa/storage/images/esa_multimedia/im...
| drewg123 wrote:
| I stand corrected. I erroneously picked up 2034 from the
| timeline. But the point still stands; 8 years is a
| depressingly long time. If we base missions on the
| discoveries of previous missions, there is an 8-year minimum
| gap between missions.
|
| I'm just hoping we find evidence of extraterrestrial life in
| my lifetime, and at this rate, we'll be cutting it close..
| twic wrote:
| Europa Clipper, which weighs about the same, is planned to
| make the same trip in five and a half years, and could have
| done it in less than three if it had launched on SLS:
|
| https://en.wikipedia.org/wiki/Europa_Clipper#Launch_and_tra
| j...
|
| Ariane 5 is not particularly powerful as interplanetary
| launchers go.
| eep_social wrote:
| This was an intentional choice for efficiency and to allow more
| science at the destination, "the final flyby.. will be 3700 km
| from Earth in November 2026" [1]
|
| Really disappointing that this is top comment tbh.
|
| [1] https://sci.esa.int/web/juice/-/58815-juices-journey-to-
| jupi...
| twic wrote:
| What? How does getting there more slowly mean more science at
| the destination? And if so, why is Europa Clipper going to
| get there much faster?
| randallsquared wrote:
| The trade-off for a given rocket is more spacecraft (and
| instruments to do science with) vs getting there faster.
| beebeepka wrote:
| Maybe slower speed means more time spent in close
| proximity. Moving things don't exactly stop on their own in
| space. Or maybe they wanted more stuff on there
| [deleted]
| JumpCrisscross wrote:
| > _How does getting there more slowly mean more science at
| the destination?_
|
| Mass. Small payload fast. Or large payload slower. (Also
| flyby vs. orbital insertion. If you're going fast, you
| don't get to loiter.)
| swarnie wrote:
| Nasa are supposedly working on it but that hasn't meant much
| since the 60s.
|
| Maybe inequality will breed a billionaire with a hard-on for
| nuclear propulsion?
| 867-5309 wrote:
| it's a shame nuclear detonations in space are banned (for
| obvious reasons)
| sfifs wrote:
| What is actually the obvious reason to ban nuclear
| detonation in space (Not planetside) other than
| proliferation & security concerns?
| floxy wrote:
| https://en.wikipedia.org/wiki/Nuclear_thermal_rocket
| binarycoffee wrote:
| One may count electric propulsion as a "better" propulsion
| system, but sadly it was a poor fit for Juice due to the very
| tight power budget.
|
| Even with those gigantic solar arrays, energy management on
| Juice is extremely challenging. Once in the vicinity of
| Jupiter, the spacecraft will be powered by less than 4% of the
| solar flux it receives in earth orbit.
| dmix wrote:
| Has there ever been a major unmanned project like this that blew
| up on takeoff/failed in orbit in recent years?
|
| I was listening to the huge list of gear they put on this thing
| by a project lead and the years of hard work by scientists and it
| would have been heartbreaking if it failed catastrophically.
|
| https://youtu.be/Ljh2BKdjpmE
| ChuckMcM wrote:
| A good summary of NASA's robotic mission failures:
| https://astronomy.com/news/2020/12/nasas-failures-robotic-sp...
| mostly early ones as NASA developed a better process and
| understanding for getting things right the first time.
| nordsieck wrote:
| Not sure if you count Zuma. Didn't really "blow up", but it did
| fail to separate from the 2nd stage.
| aeroman wrote:
| There were a few Earth Observation missions that didn't make
| orbit about 10-15 years ago. This was due to a failure of the
| Taurus-XL fairing separation.
|
| The orbiting carbon observatory (OCO) failed to reach orbit in
| 2009 [1]. It got a replacement (a good thing, given how
| important these measurements are.
|
| Glory [2] would have had a really cool polarimiter (measuring
| light polariasation as well as radiance, in a range of
| different directions, but it failed in 2011 for the same reason
| as OCO. Unfortunately, it didn't get a replacement.
|
| [1] - https://en.wikipedia.org/wiki/Orbiting_Carbon_Observatory
|
| [2] - https://en.wikipedia.org/wiki/Glory_(satellite)
| progbits wrote:
| During the JWST streams I recall hearing this is why they went
| with the Ariane 5 as it is the most reliable launch platform.
| It might not be fancy, reusable or even fastest or most
| powerful, but it will reliably lift the payload, not explode,
| and deliver it to orbit at just the right speed. Same rocket
| was used for Juice.
| ChuckMcM wrote:
| I'm looking forward to the results from this one. In particular
| the idea that is discussed in the article about Ganymede's
| magnetic field. Jupiter's orbit has a mess of radioactivity and
| it would be really helpful if Ganymede's magnetic field made it
| possible to exist on the surface without massive amounts of
| shielding.
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(page generated 2023-04-14 23:00 UTC)