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The Voyagers took advantage of a special constellation that doesn't happen often: "In the 1960s, mission designers at JPL noted that the next occurrence of a o

The Voyagers took advantage of a special constellation that doesn't happen often: "In the 1960s, mission designers at JPL noted that the next occurrence of a once-every-175-year alignment of the outer planets would happen in the late 1970s. A spacecraft could take advantage of this opportunity to fly by Jupiter and use its gravity to bend its trajectory to visit Saturn, and repeat the process to also visit Uranus, Neptune, and Pluto." https://www.nasa.gov/feature/45-years-ago-voyager-1-begins-its-epic-journey-to-the-outer-planets-and-beyond https://www.nasa.gov/feature/45-years-ago-voyager-1-begins-i...

perihelions 4y ago
That didn't affect the Earth-Jupiter leg, which was direct.
- GravitasFailure 4y ago
  If I'm reading the specs correctly the Titan IIIE was a significantly more powerful vehicle than the Ariane 5 while launching a much smaller payload. JUICE also has to be going slow enough to enter orbit without carrying an insane amount of fuel for braking while Voyager just did a flyby.
  - perihelions 4y ago
    - "Titan IIIE was a significantly more powerful vehicle than the Ariane 5 while launching a much smaller payload" Yes, with a fourth stage. (I don't think it's particularly that modern rockets can't integrate such a solid-rocket boost stage, but rather there's no payload that needs this). https://en.wikipedia.org/wiki/Star_(rocket_stage) https://en.wikipedia.org/wiki/Star_(rocket_stage) - "JUICE also has to be going slow enough to enter orbit without carrying an insane amount of fuel for braking while Voyager just did a flyby" The flyby speeds are similar; but JUICE takes a time to get to that speed. It's not really that difficult to capture into Jupiter. Parent's link [3] says it's only 900 m/s for JUICE. Part of the reason is the extremely deep gravity well; and another is that the moons are large enough to give you effective gravity assists, within the orbit of Jupiter.
    - GravitasFailure 4y ago
      >The flyby speeds are similar; but JUICE takes a time to get to that speed. Ahhh, that makes sense. Essentially Voyager did do a direct flight while JUICE isn't, instead building speed by doing slingshots off Earth and Venus. "First, it will do a fly-by of Earth and the Moon, then slingshot around Venus in 2025 before swinging past Earth again in 2029." https://phys.org/news/2023-04-europe-juice-mission-jupiter-icy.html https://phys.org/news/2023-04-europe-juice-mission-jupiter-i...
    - raverbashing 4y ago
      Yes the problem is not only getting to Jupiter, it is stopping once you get there
deleted 4y ago
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perihelions 4y ago

That didn't affect the Earth-Jupiter leg, which was direct.

GravitasFailure 4y ago
If I'm reading the specs correctly the Titan IIIE was a significantly more powerful vehicle than the Ariane 5 while launching a much smaller payload. JUICE also has to be going slow enough to enter orbit without carrying an insane amount of fuel for braking while Voyager just did a flyby.
- perihelions 4y ago
  - "Titan IIIE was a significantly more powerful vehicle than the Ariane 5 while launching a much smaller payload" Yes, with a fourth stage. (I don't think it's particularly that modern rockets can't integrate such a solid-rocket boost stage, but rather there's no payload that needs this). https://en.wikipedia.org/wiki/Star_(rocket_stage) https://en.wikipedia.org/wiki/Star_(rocket_stage) - "JUICE also has to be going slow enough to enter orbit without carrying an insane amount of fuel for braking while Voyager just did a flyby" The flyby speeds are similar; but JUICE takes a time to get to that speed. It's not really that difficult to capture into Jupiter. Parent's link [3] says it's only 900 m/s for JUICE. Part of the reason is the extremely deep gravity well; and another is that the moons are large enough to give you effective gravity assists, within the orbit of Jupiter.
  - GravitasFailure 4y ago
    >The flyby speeds are similar; but JUICE takes a time to get to that speed. Ahhh, that makes sense. Essentially Voyager did do a direct flight while JUICE isn't, instead building speed by doing slingshots off Earth and Venus. "First, it will do a fly-by of Earth and the Moon, then slingshot around Venus in 2025 before swinging past Earth again in 2029." https://phys.org/news/2023-04-europe-juice-mission-jupiter-icy.html https://phys.org/news/2023-04-europe-juice-mission-jupiter-i...
  - raverbashing 4y ago
    Yes the problem is not only getting to Jupiter, it is stopping once you get there

deleted 4y ago

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