(Mind the Pohl.)
We've been discussing Venus' egress at trailing Trojan L5; that it is normally bypassed by Earth, and so makes an oasis for general not-Earth system affairs. Let's discuss what leading Greek L4 is for. I don't think it will be bypassed by Earth, or by anyone else.
I am informed George O Smith got here first with his Venus Equilateral Relay Station stories 1942-5, but I confess I haven't read 'em. They assume that Venus and Mars are colonised... as do I, in my way. The VERS is built out of a three mile by one mile asteroid moved into L4's loop, which I can also accept. A 2.53-7.75 km2 visible surface-area / 2000 m diameter rock doesn't currently live near Venus; but this scale of rock does on occasion approach Earth, and we can catch such and move it thither. We'll just have to agree to disagree on the vacuum-tubes on the one side of modern tech, and on the "driver-tube" propulsion on the other.
Earth/Moon arrival at SVL4, preceding 2225 arrival, correlates to .943 so 10 December 2224. Note: before even Conjunction / "Advent", 23 January 2225. Also people can trickle into the L4 and L5 plateaux for many days and even weeks before and after; the range of stability is wide.
L4s are in the direction of revolution so anything arriving there is moving away from the planet... at first. But do keep in mind it is a libration. Once there any craft will be turning around toward the planet, later.
One advantage Venus L4 has over L5: SVL4 is more easily supplied from Venus than is SVL5 at other times, shot out via her retroretrograde-orbiting colonies. L4 makes a staging site for outworlders (including Luneys; and such Earthlings as took the cheap seats) intending a long term at Venus, with more time to spare than the direct Hohmann liners.
At L4, such board parabolic ships. These accelerate, gradually; then go to freefall at the aphelion; then decelerate more and more strongly until a Venus-orbit station is reached - at around the same time as their compatriots there by direct Hohmann. But now the outworlders can handle the heavy Venus G.
I'd further suggest that L4 is a good place to catch hydrogen (protons) and helium (alpha rads) blown off from the solar wind. Further: the waste from ships hopping out of here is mostly water vapour, which will leave ice behind, at something of a premium in the Venus tier.
L4 will host the Solar System shipyard, in the shade of those radiation-catchers. This is where the minerals and boilerplates are refined and assembled. It is, further, the best entrepôt for shipments from Mercury via Hilda Cycler. And, I think, here is where it is all traded. So here is the System stock-exchange.
ELEVATION 12/6 - The first version was posted Wednesday. I've added the para on catching rocket-fuel and recapturing water.
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