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I've been doing some research to figure out how feasible grand tour manned missions to the surface of the moons of each outer planet.

This is related: Where can I find a delta v map of landing requirements, not transfer requirements

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    $\begingroup$ Are you really asking about Delta V, or the time and energy required to achieve it? $\endgroup$ Commented Oct 12, 2023 at 20:10

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Most search results I get for "solar system delta-v map" includes this information. I quite like this one:

enter image description here

To read out the ascent cost from these maps, you take the single number between the "surface" and "low orbit". This is generally the minimum required to not fall back on the ground, but without any transfers to other planets or orbits included.

The ascent cost and descent cost will generally be the same, as these are symmetrical. Atmospheres complicate this somewhat, as you can land on those bodies "for free", by slowing down with a heat shield. Ascent on the other hand gets a little more costly due to drag, and this will vary depending on the spacecraft you are using.

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    $\begingroup$ a note for less-experienced readers / those who haven't played KSP: ascent and descent are also complicated by thrust (or drag) requirements. You probably can't take off or land with ion thrusters, even if they'd give you a ton of delta-V once you're in orbit. $\endgroup$
    – Erin Anne
    Commented Oct 11, 2023 at 23:55
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    $\begingroup$ @ErinAnne I take it the numbers here are calculated assuming an 'instantaneous pulse', i.e. not taking into account the time needed to accelerate to that velocity, meanwhile fighting against gravity? $\endgroup$
    – Ingolifs
    Commented Oct 13, 2023 at 0:08
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    $\begingroup$ @Ingolifs I didn't calculate the numbers, make the image, or post this answer. LEO velocity is more like 7km/s so the 9.0km/s shown in the image appears to include some losses, though the assumptions the poster made aren't entirely clear. $\endgroup$
    – Erin Anne
    Commented Oct 13, 2023 at 3:17

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