• Skua
    link
    fedilink
    42 months ago

    I’ll wave as it goes by!

    Since launching last year, this is JUICE’s first gravity assist. The rest of the route is Venus in a year, Earth again a year after that, three years of being flung out beyond Mars before falling back to pass by Earth in 2029 for one final gravity assist to get all the way to Jupiter

  • LostXOR
    link
    fedilink
    22 months ago

    Interesting that they opted for the “massive gravity assist chain” route instead of just using a more powerful rocket capable of a direct transfer to Jupiter. Sure, it’s cheaper, but we have to wait a whole 8 years for it to arrive instead of ~3.

    • teft
      link
      fedilink
      English
      52 months ago

      It would be prohibitively heavy to get a probe on an earth-jovian direct trajectory using just propellant.

      You’d have to launch 20 missions before JUICE just to get enough fuel into space to get juice to jupiter. And then you also need to think about how you’d perform an orbital insertion at that speed (hint: you can’t) so you’ll need double the rockets for braking fuel.

      40 missions for one space probe is not worth it for any science endeavor.

      • @Gsus4
        link
        English
        1
        edit-2
        2 months ago

        Oh, I never noticed that, I thought they just did a transfer orbit, but yea, in all Jupiter orbiter missions so far they did all of these convoluted gravity assists. I see both Juno and Galileo did it (about 5y travel time).

    • Skua
      link
      fedilink
      52 months ago

      The Ariane V is one of the most powerful rockets ever built in terms of the capacity it can take to orbit. SpaceX’s Falcon Heavy and China’s Long March 5 can beat it, but neither has anything like the extensive service record of Ariane V nor had they flown at all when the probe was being designed. Plus of course, any space agency is always going to be more inclined to use domestic rockets that they’re already very familiar with