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How fast can we build and launch something to rendezvous with this dwarf planet?

• jessriedel 5y ago
  New Horizons took a nearly straight shot to Pluto (just stopping by Jupiter on the way for a gravity assist). That trip took 9 years to travel 40 AU (not at constant speed, of courses, since it's constantly being drawn toward the Sun). This dwarf planet makes its closest approach at 10 AU, so you could do a fly by in less than 3 years if you wanted to pay for it. However, the science return from a flyby would be limited compared to falling into orbit around it. Rosetta took 10 years to match pace with and orbit a comet (which had a closest approach to the Sun less than 1 AU) using a number of gravity assists. https://raminskibba.net/2014/08/17/rosetta-and-the-comet/amp/ https://raminskibba.net/2014/08/17/rosetta-and-the-comet/amp... https://raminskibba.files.wordpress.com/2014/08/f4-large.jpg?w=600&h=430 https://raminskibba.files.wordpress.com/2014/08/f4-large.jpg...
  • messe 5y ago
    Getting into orbit would be rather difficult, as the probe would have have to match the planets velocity at perihelion. My instinct says it’s probably just on the edge of doable (although I’m not sure on which side), but I haven’t crunched the numbers. It would almost certainly need to be launched on a Delta-IV or Falcon Heavy class vehicle. EDIT: s/perigee/perihelion. I could say periapse and be neutral, but perihelion sounds cool.
    • jessriedel 5y ago
      The speed of Rosetta's comet at perigee is, I think, significantly grater than the max speed of this dwarf planet. The dwarf planet has a much higher apogee, of course, but escape velocity, corresponding to infinite apogee, is finite and not that large, and Rosetta had to go much deeper into the Sun's gravity well. So, as a non-expert who hasn't done the numbers, I'd guess matching pace with the dwarf planet would be easier (requiring less delta V and/or gravity assists) than Rosetta with the comet.
      • messe 5y ago
        Somewhat unintuitively, thanks to the Oberth effect, it can be easier to reach escape velocity closer to an object, (Humorously portrayed in https://xkcd.com/1242 https://xkcd.com/1242). Aside: if you are looking to learn more, I cannot recommend Kerbal Space Program enough.
        • thoughtsimple 5y ago
          I think you meant: https://xkcd.com/1244/ https://xkcd.com/1244/
          • messe 5y ago
            Whoops. Yep, that’s the one. Maybe I’ll be vindicated when it turns out the planetoid is made out of grey goo.
        • perl4ever 5y ago
          I've been aware of people talking about Kerbal Space Program for years and years, but I lost interest in playing it when I heard it didn't do real N-body gravitational calculations because they were too intensive. I still find that inexplicable. To me, it sounds like saying "our calculator only does basic arithmetic on four core machines, square roots are too slow".
          • messe 5y ago
            Not really that inexplicable, it’s a video game. It’s not for computational reasons, but to make gameplay easier to reason about; because again, it’s a video game. The mechanics are simplified, yes, but patched conics is quite a good approximation for many cases, and great for developing an intuition for the basics. There is a mod that includes n-body calculations called Principia if you’re interested in that.
            • deleted 5y ago
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    • perihelions 5y ago
      It's difficult to believe that ten years from now, there'd be any serious options other than Starship and its future peers. (Incidentally, the Delta IV is already at end-of-life; ULA is replacing it with Vulcan and its Blue Origin engines. The final Delta IV-H launches are planned for 2023). https://spacenews.com/ulas-delta-4-heavy-down-to-final-five-missions/ https://spacenews.com/ulas-delta-4-heavy-down-to-final-five-...
      • messe 5y ago
        I more meant that it would take at least that size-class of heavy lift launch vehicle. With Starship this would definitely be doable, and I’m really optimistic about it; I just wanted to be cautious in my predictions. I also wouldn’t be surprised if Delta IV’s life gets extended. Vulcan is facing plenty of development delays, and Blue Origin are yet to produce anything useful.
        • deleted 5y ago
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    • ramraj07 5y ago
      Might there be not some benefits to try to get into orbit around this object, like perhaps a free ride to the Oort Cloud maybe?
      • jfengel 5y ago
        There's no such thing as a free ride. If you can soft land on it you're already going to the Oort cloud. You could get a free ride by having it crash into you, but that's going to be like catching a bus by letting it hit you, at ten thousand miles an hour.
    • perl4ever 5y ago
      In a few years, can't we look forward to SpaceX making it routine to refuel in orbit? If we assume that's feasible, I wonder what sort of missions it would enable, other than human spaceflight.
      • messe 5y ago
        Hopefully yes. I was being conservative with my suggestions.
    • throwaway316943 5y ago
      Maybe starship will be ready with orbital refueling in time to make a faster trip. Imagine being able to do a sample return mission from such an object.
    • deleted 5y ago
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  • yummybear 5y ago
    I would assume planning and budgeting would also take up a lot of time.