From Mercury's orbit to Venus'

Last night I mused on the 3:2 Venus-Hilda Cycler's orbit, how to protect its natural stability from a Mercury crash. And, if you read that post, and did any math on it ... you'd have found out that I was wrong. (I've fixed that post since.)

But also at that time I wondered: what if we used this cycler for shuttle from Mercury's orbit, via its own orbit, finally nearer to Venus' orbit. That much, I can salvage. Even if the cycler only runs to 0.578 AU.

Forewarning: Hilda doesn't go to Venus itself. She just goes to points with ballistic access to Venus. From perihelion, her aphelion disembarks toward L4 - the shipyard. "Toward" because this variant only gets within 0.115 AU of L4 proper.

For our purposes we define "Mercury" as its L1 / L2 gravity-well, which Hop David's xls defined as a sun-biased 220000 km radius ellipsoid. At 1.1° upward of Venus, 2.5° apart, a Hilda cycler and Mercury can at closest meet 0.02 AU apart. That’s thrice Venus’ own L1 gravity-well. Or: since an AU is 149,600,000 km, 0.02 AU is 7.8 times the 384,400km Earth-moon distance; for that, Apollo 11 took three days, 16-19 June, into Lunar orbit.

What Mercury’s emigrants want is to match Hilda’s speed and angle at its perihelion. I should point out that Mercurians rarely meet Hilda’s perihelion when Hilda is closest to Mercury. Some Hilda cycles will take more of Mercurians’ time. I imagine anytime from one to ten weeks. The good-ish news is that Mercury mostly exports heavy metals, which should shield any outgoing humans.

From perihelion (here, on the Venus upside of Mercury’s well) to aphelion (L4), Hilda will coast for 1/3 a Venus year, a cool (well, warm) additional 75 days.

For shuttles on that cycler that is a straight run from 0.578 AU over. That is 0.115 AU against Solar gravity; and an additional push up-ways for that 1.1° angle.

0.12 AU mightn't seem like That Much here on Earth but, we're almost twice as far from the Sun. Also 0.578 AU will have inverse-square less direct Solar radiation than what Mercury usually gets at 0.387. On the other hand, Hilda did get us to 0.578 AU. Maybe the L5 college students will figure this one out. WHAT IT LOOKS LIKE 1/2020: A pre-Rama seems like the ticket.

Assuming they do : this further implies that the first Mercury-Hilda cycler's run will swing by Venus when that planet is (also) perihelical. One such perihelion occurred 26 December, 2018.9863104. So after October 2224 Carnivale: 0.0776404 year into 2225, 28 January. It gets to L4, 13 April.