As for refuting your earlier points, here goes:
- The 'assuming you're right, so what, we don't have any of them so it's not a problem' is wrong because we've been told we could make them and they would be practical. If we could make them and they defied how orbital mechanics in our world work, then that would mean that they don't apply here.
- Those are two Lagrange points (more on these later)—L1 and L2 under most common nomenclature—and the 'only' issues with having our shipyard there would be that you couldn't have minefields and defense stations around it effectively, as the spread needed to have coverage would mean you'd have mines going off in all sorts of odd orbits around either the moon or the planet, made worse by the fact that they're unstable Lagrange points. Some active stationkeeping by the yards in question would also be required. The main issue here is that we were told that the lifts themselves would be vulnerable, not that it would require moving our shipyard into a more vulnerable location (to say nothing of the issue if that would move the shipyard out from 'over' a city).
- If a moon isn't tidally locked it's a different matter, but that just means it goes from obviously and ludicrous impossible for a traditional geostationary orbit (which lets you be 'over' any part of the moon's equator) to merely highly unlikely. The Hill Sphere (which is the formula I used for figuring out the maximum distance of a stable orbit around a moon of a planet) is still fairly small for a moon, and unless it is itself spinning rapidly it's unlikely to be within it. As an aside, if the moon is NOT tidally locked, the Lagrange point cheat for a pseudo-geostationary orbit doesn't work.
- In this point you're either talking about the Lagrange points again or just orbiting the moon. There is nothing stopping you from orbiting the moon in workable orbits. The issue is that none of those keep you 'above' the same part of the moon (a requirement for any sort of spire/elevator). By orbiting the moon you are also orbiting the planet, as the moon is orbiting the planet. The issue is that if you get too far from the moon the forces the planet puts on you and the moon start to diverge beyond the ability of the moon's gravitation pull to compensate for, which causes you to transfer into a different orbit of the planet than the moon's.
- This point is that with the super-advanced reactors we can have our stuff be unstable orbits, which is true. However, as I pointed out, if lift/boosting was free there would be literally no point to an orbital elevator. If we have our shipyards in an unstable orbit, we would need to constantly boost all of our shipyards. Now, a bit of stationkeeping for something on that scale is fine, but to be enough to significantly change what orbits are okay would be far, far more thrust than taking parts up would be. Like, absurdly. All the time.
- You can orbit multiple objects at once—for example, the sun orbits the center of the galaxy, the earth orbits the sun, the moon orbits earth and the sun. The caveat is that effectively each object has a limited area where they are the thing that gets orbited, known as the Hill Sphere, and if you're outside of that you're just going to be orbiting the thing it orbits. Small (relatively speaking) moons around big gas giants do not have a very big Hill Sphere.
Now that I've hopefully cleared up any ambiguity on the points you brought up last post, let's move on to the current post's issues.
My point was not that having the docks in orbit around the moon of the gas giant was impossible, it was that having them in a geosynchronous orbit was, as no traditional stable geosynchronous orbits exist. The shipyards could be placed in a Lagrange Point (which is what the lunar elevator you linked uses), but in addition to mandating exactly what part of the surface of the moon they're 'above', generally speaking the stable members of these points (which would be required for any major defenses to be in place on location) are also far enough away from the moon in question that they would not be 'close' to the moon from a defensive (and to some extent a logistical) standpoint, and the limited size of the relevant points means that mining the approaches would be effectively impossible.
My understanding for how the current setup
could work with our orbital mechanics would be if the space docks etc were in a relatively low and fast orbit around the moon, with higher orbits and the like holding defense stations and minefields. Even then you run into some issues with scale, but if you don't look too closely it seems okay. No need for rule of cool
until you start talking about orbital lifts/spires from the surface of the moon to the heavily defended shipyards, at which point things start to get quite a bit more complicated.
As for the 'most moons' issues, this is the rule. There are, of course, exceptions to the rule. The thing is, an exception to the rule is the unlikely outcome. The idea of an orbital lift for our shipyards was not treated as something that a unique confluence of events made theoretically feasible, it was treated as something that could easily be on the upgrade path of any shipyard orbiting something, be it a moon of a gas giant or a planet.
Also, as I pointed out earlier, the Lagrange point approach flat out doesn't work for moons that are not tidally locked, and with the very limited size of the Hill Sphere of a moon orbiting a gas giant combined with the fact that the tidal forces are still going to have increased its rotational period even if it hasn't yet started to reach the point of tidal lock, the odds of a relatively stable geostationary orbit are still damn near nil.
