from Hacker News

ESA’s Juice lifts off on quest to discover secrets of Jupiter’s icy moons

by Tevias on 4/14/23, 8:17 PM with 65 comments

  • by drewg123 on 4/14/23, 9:37 PM

    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.

  • by jmyeet on 4/14/23, 11:51 PM

    I'm glad to see this flagship interplanetary probes launch. For those wondering why it's taking 8 years, it's huge (~6 tons IIRC).

    I still hope to see probes enter orbit around Uranus and Neptune in my lifetime. Neptune in particular would be a massive challenge with an expected flight time of ~30 years IIRC so I don't see that happening anytime soon.

    The last (and only!) time we've been to Uranus and Neptune is with Voyager 2 in flybys in 1986 and 1989 (respectively). Imagine what we can do with current technology. I guess a flyby is the most we can hope for. Still, I can dream.

  • by ChuckMcM on 4/14/23, 9:29 PM

    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.

  • by dmix on 4/14/23, 9:03 PM

    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

  • by macintux on 4/14/23, 10:01 PM

  • by ggm on 4/15/23, 3:16 AM

    Would more energy be available for capture from Jupiter's reflectance or direct from the sun? My heart wants to say yes but my head thinks even as a point source, direct solar energy is higher.

    If it was other RF or heat, maybe not. I wonder if a Stirling engine could work alternating shade and Jupiter's direct radiation?

    I also wondered if lowering a long tail could acquire electrostatic energy greater than its coefficient of drag. As above, cute but .. no.

    The proof by example answer is "if it had been viable they'd have done it"

  • by kumarvvr on 4/15/23, 2:26 AM

    With the likes of SpaceX being around, is it not possible to have a store of fuel in orbit, so that these missions can pick a tank or two of them, slingshot their way and use the fuel to speed up the journey?

    Or, is it purely economics at play?

  • by karaterobot on 4/15/23, 1:24 PM

    I hope it's still around 15,000 years from now, watching increasingly absurd variations of football games.

  • by euroderf on 4/16/23, 4:16 PM

    This was the first video of the actual liftoff that I have seen. I looked for something a few hours after liftoff but came up with nada. I can compare this to US missions: there is always something quickly on Youtube, clearly marked.

    ESA get your social media presence in gear !

  • by rufus_foreman on 4/14/23, 10:47 PM

    I guess plume flybys technically don't count as attempting a landing?