Skydock should not be feasible


General Discussion


I think it’s great that the Starfinder setting has a space elevator. It’s a really cool idea, and a far-future setting deserves some advanced but not outlandish technology like that. There’s just one problem. It should never work on Verces.

The space station at the end of a space elevator tether has to be in geostationary orbit (technically just a bit beyond). Verces, though, is a tidally locked world. It doesn’t *have* a geostationary orbit, unless you want to count Lagrange points. The nearest Lagrange points, though, would still be at least a million kilometers from the planet, and those would be above Fullbright and Darkside, not the Ring of Nations.

So Skydock should not stay in orbit, at least not based on science. Magic would have to keep it up. But if the Verthani have sufficient magic to levitate a space station big enough to hold nearly a million people, why would they even need a space elevator and why wouldn’t they have all sorts of other advanced gravity-defying techno-magic?

(As an aside, Akiton, on the other hand, is a small world with low gravity and a normal day-night cycle, not to mention a thin atmosphere. It would be technologically feasible (and fairly urgent) for an advanced society to build a space elevator there. If it wasn’t such a fundamental change to the game setting, I’d be tempted to switch it in my game.)

Am I nitpicking? After all, this is a universe with cities inside the sun. Except those are clearly described as being sustained by magic far beyond the Pact World races’ capabilities. The Verthani, on the other hand, are still around and no more advanced than the rest of the Pact Worlds. It’s an unfortunate inconsistency, in my mind, but it would also be tricky to correct. Nevertheless, I’d like to come up with an explanation for Skydock that doesn’t sound completely contrived. Any ideas?


I am no astronomer, not by any means, but isn't a tidally locked world that far from its co-orbiting body, with that much stuff in-between them, weird in the first place ?
And isn't the issue with geostationary orbit around a tidally locked body that the distance needed would normally exceed the distance between said co-orbiting bodies, which might not be as much of a problem when talking about the 4th - formerly 5th - planet from the Sun and said very same sun.
Again, not my expertise by far, but I suspect that's an uncommon proposition.

And it's not exactly the only abnormal thing in the system.
Either SF's physics simply obey different rules, or there's enough magical, divine and otherwordly interference on top of each other to make it at least partly irrevelant.
I mean, even Golarion's disappearance itself hasn't had that much impact on the system - although I guess we don't know how long ago it happened.

My point being that I'm not sure it has to make sense. The weirdness could be the point.
Plus all those tropes need to be used somewhere, and this is most definitely not a hard science setting.

That said the dilettante in me is still quite curious, and hoping we get a more scientifically accurate answer.


Yes, a planet with a 3-year period around a sun-like star should not become tidally locked through any natural means. I let that one go because of a reference in the Pact Worlds book - in the description of the "Singing Rifts", the setting suggests there's an unnatural reason for Verces to be tidally locked. Ancient alien machinery (or magic) is a standard trope for sci fi or fantasy settings.

Perhaps that's exactly what I could invoke for Skydock. Like the Starstone on Absalom Station, there could be some powerful artifact of unknown origin that the Verthani placed on Skydock to keep it from falling. It could be related to the Singing Rifts, the Oasis Temples or the Enigma Keeps.

And yes, Golarion's disappearance should have a ripple effect on the orbits of other planets in the solar system, but that could take a very long time to cause appreciable changes or it could have been stabilized by whatever power removed Golarion.


Just brainstorming here, because I'll need to take some serious liberties with the term "tidally locked". Let's change it to "a solar directed polar orientation", a la Uranus (a planet "on its side").

Granted, even that would only allow for a migrating habitable-band, as the planet's North would procede as it revolved around its primary, and not stay pointed at the Sun.

(sigh) No, this type of planet would normally happen at or about the orbit of a Mercury-class planet. Or as the moon of a large Giant.

The only things that could mess with gravitational physics at this level would be multi-Deity interactions. Or a game-design that didn't actually involve astrophysicists for sanity-checking.


A couple of C8 thrusters will take anything anywhere.


Pathfinder Adventure Path, Lost Omens Subscriber; Starfinder Charter Superscriber

Sounds like a good story hook. Clearly there is powerful magic or an artifact involved. The PC's could be attempting to investigate the mystery on behalf of a third party, or trying to stop terrorists from destabilizing it, or both (with their would be beneficiaries turning out to be said terrorists).


DochSavage wrote:
Just brainstorming here, because I'll need to take some serious liberties with the term "tidally locked". Let's change it to "a solar directed polar orientation", a la Uranus (a planet "on its side").

I agree that "tidally locked" isn't really accurate (nowhere near enough gravity gradient), but Verces is described as having no axial tilt and a rotation rate that precisely matches its revolution rate, so it *acts* like it's tidally locked. I see what you mean about changing it to behave like Uranus, which would allow for a geostationary orbit, but yes, that would mess up the Ring of Nations idea.

I think I'll stick with the powerful artifact explanation. That's a relatively small setting change that preserves suspension of disbelief and, as mentioned, throws in a new story hook for adventures on Verces.

But I may also play with the idea of an Akitonian Skydock as an alternative to the current setting. That would involve significant back story changes and alterations to the current dynamic in the Pact Worlds, but that appeals to the writer/storyteller in me.


From a physics perspective, unless Verces has other moons that would pull Skydock out of orbit (as it the case with the Earth's moon pulling geosynchronous objects out of sync), there there's not reason Skydock couldn't be in a stable, synchronous orbit. Verces is tidally lock, but that doesn't mean it doesn't rotate. It just means it rotates (around it's axis) at the same rate as it revolves (around the sun). Because of the atmosphere and gravitational effects of the planet (and the drag from the elevator) it already MUST be equipped with navigational and stabilizer thrusters or it would fall out of orbit anyway. However, as long as it doesn't pull any delta-Vs (one way or the other), and it can counter the frictional drag, all it needs to do it ensure it's orbital velocity and vector matches the rotational velocity of the planet and you'll have a stable, synchronous orbit.

Consider Pluto and it's moon Charon for example. They are mutually tidally locked. It's not a perfect example since Charon is really large for a moon, so they sort of orbit each other... but it's still a good case in point.


I'm tempted to make a reference about magical artifacts up space elevators, but I can't even mention where it's from without spoiling a major plot point.

Sovereign Court

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Magic or thrusters keeps it up. Why build it? Long term it's cheaper than using magic or space flight. Once you build it, you simply maintain it - the longer it exists, the more it pays off.

Also, it seems like a common trope that the super magic civilization burned out a long time ago, so they stopped the planet, but now they are gone. The magic that caused the tidal-lock no longer available for current people to use.

Instead they built a space elevator.

What they didn't tell you is it's NOT a space elevator. It's a rocket ship tethered to a planet. Someday that rocket ship is going to kickstart the rotation again.

You just need to be patient.

Enjoy the cheap space flight while it lasts. :-P


Kvetchus, while you're technically correct, the geosynchronous distance for Verces would be over 4 million kilometers away from the planet, assuming no other gravitational influence (which would be a bad assumption), and that's clearly an absurd distance for a space elevator, not to mention farther than a couple of the Lagrange points. There's a massive difference between the thrusters required for station keeping in a stable geosynchronous orbit and the thrusters required to keep a space station hovering over a planet and not in an actual orbit.

Trentin, actually "space elevator" is exactly how it is described in the core rulebook. Interestingly, though, while I think the books *imply* the Verthani built Skydock, it doesn't actually say they built it, just that it is ancient, it predates the Gap, and it gave the Verthani cheap spaceflight. I suppose one could say that Skydock, itself, is an ancient alien artifact left for the Verthani.


Faragdar the Free Captain wrote:
Kvetchus, while you're technically correct, the geosynchronous distance for Verces would be over 4 million kilometers away from the planet, assuming no other gravitational influence (which would be a bad assumption), and that's clearly an absurd distance for a space elevator, not to mention farther than a couple of the Lagrange points. There's a massive difference between the thrusters required for station keeping in a stable geosynchronous orbit and the thrusters required to keep a space station hovering over a planet and not in an actual orbit.

Well...... ok, yes, there's the mass equation. But maybe the core of that station is made of some sort of ultra-dense unobtainium which allow the station to remain in a closer orbit, and the station-keeping thrusters are all actually massive, but only give it a little nudge :)

I mean, at the end of that day, none of this is realistic anyway, so I guess... who cares? To heck with physics - it's all space magic :)


Meh, just say it's physically anchored to the planet and they sue incredibly strong materials to keep everything in place. Materials that they did not create nor have access to more. Sure, such materials would have to be impossibly strong, but the point is you can make up all sorts of reasons to justify this even if the physics say it shouldn't happen.


The Sideromancer wrote:
I'm tempted to make a reference about magical artifacts up space elevators, but I can't even mention where it's from without spoiling a major plot point.

That wouldn't happen to be a reference to

SPOILER ALERT:
the Dire Earth Cycle,
would it?

Vutava wrote:
The Sideromancer wrote:
I'm tempted to make a reference about magical artifacts up space elevators, but I can't even mention where it's from without spoiling a major plot point.
That wouldn't happen to be a reference to ** spoiler omitted ** would it?

That was not the one I was thinking of. I was thinking of an rpg video game.


Pathfinder Starfinder Roleplaying Game Subscriber
Claxon wrote:
Meh, just say it's physically anchored to the planet and they sue incredibly strong materials to keep everything in place. Materials that they did not create nor have access to more. Sure, such materials would have to be impossibly strong, but the point is you can make up all sorts of reasons to justify this even if the physics say it shouldn't happen.

You know, the setting actually *does* have access to a relatively cheap and easy "indestructible" material: force effects, like Walls of Force. Even at a fairly low level, these can produce structures that are impossible to break with physical force. Its not actually inconceivable that they built the Skydock with a "rod of force" at its core providing all the structural integrity.

Second Seekers (Luwazi Elsbo)

Metaphysician wrote:
You know, the setting actually *does* have access to a relatively cheap and easy "indestructible" material: force effects, like Walls of Force. Even at a fairly low level, these can produce structures that are impossible to break with physical force. Its not actually inconceivable that they built the Skydock with a "rod of force" at its core providing all the structural integrity.

Sorry to necro!

That is my assumption --
An artifact, likely pre-Verthani, keeps Skydock station-keeping several hundred kilometers aloft, but well below the multi-million kilometer geosynch or geostationary orbits.

Good news: things you drop won't orbit with you and maybe hit you in the back of the head when you aren't looking.

Bad news: things you drop WILL hit Verces' turbulent atmosphere and Fullbright's dayside to Darkside's nightside hurricane winds...

Headcanon:
Verthani used this unusual structure to build their first aetherships and "dive" off the platform toward Verces, skimming close to the atmosphere for slingshot burns that enabled their graceful, low impulse aetherships to then traverse the Pact Worlds long before the later spaceships that would jet around the Pact Worlds with thasteron-fueled drives (a fuel not much mined and used until Akiton joined the spacefaring worlds).

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