Wednesday, March 31, 2021

The efficient ballistic

I am pondering the errata. Never mind the porkchops, those are a dodge. And yes, sticking with inclination-dominant cyclers, like I did with Earth-Venus, lies in that subset of "dodge".

The cyclers' maths were designed for Earth-return. There is only one run by Mars before cycler-repeat. (If that: cf. 5S8.) Something may do plenty of runs past 1.53 AU or wherever, but no more than one run by the red planet - per synod. Hence my assumption that the second visit to Mars would be at the same place at the same angle. I question here if the cycler is headed on that same angle.

The whole point of Russell-Ocampo '04 was to provide an array of angles running past Earth.

Why is V at Earth not an array? I mean, maximum angle makes the turnratio, but shouldn't we have their lower Vs too? Leaving aside that I personally don't yet know what those are for h>3 cyclers.

And wouldn't this be a fine place to consider Earth eccentricity and inclination on return?

I would set for each cycler a table of seven rows. Each seventh corresponds to the 51° angle-increment Earth has proceeded over the 15/7 years of the Earth/Mars synod. The row has a pair of vectors for Earth: position and velocity. Any return to Earth will hit one of these rows, depending on how many synodic periods p have elapsed. For Aldrin's 1-0-1-6 it's just the next one, for backflip's 2-1-1-5 skip to two and so on. The 7- series are, like VISIT, often "degenerate" but, not all of them; they stay on the same row.

This multiplies complexity such as to explain why Russell and Ocampo didn't want it. I insist on Martian eccentricity but, yeah, what I've just outlined seems like porkchop.

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