Artificial Gravity and Space Stations,

[Sagasa]

First of all, I'd like to say hello to everyone! I stumbled across this amazing game while procrastinating on tvtropes and I've been hooked ever since. I think games that don't hold the player's hand and don't force them to follow rails are the best type of games since they engage your imagination and encourage you to use your storytelling skills to fill in the gaps. I love just cruising through the cosmos pretending to be COMMANDER MICHAEL GRAY: HERO OF THE GALACTIC COOPERATIVE.

One of my hobbies while playing the game is coming up with in-universe justifications for the stuff I see while flying around. One thing that I've found a bit hard to explain is why the space stations spin around. Obviously centrifugal motion in a space station to simulate gravity is not a new concept in science fiction but in stories I've read in the Oolite Archives, artificial gravity is mentioned. This brings up the question of why these tiny, one-man ships can have the mechanisms needed to generate their own gravity field while space stations which are far, far larger don't and need to spin instead.

I tried justifying this by thinking decks within ships are arranged perpendicular to the direction of the thrust to provide a simulation of gravity while the ship is moving but this fell apart when I saw a drawing of a Cobra Mark III's interior.

Hence, I'm forced to conclude that space stations do in fact have their own artificial gravity generators and merely spin to separate the boy-pilots from the men-pilots. A kind of stellar darwinism if you will.

Your thoughts?

[cim]

Hence, I'm forced to conclude that space stations do in fact have their own artificial gravity generators and merely spin to separate the boy-pilots from the men-pilots. A kind of stellar darwinism if you will.

Your thoughts?

Station spin seems to have the aim of about 10G at the edges (for a coriolis at standard spin rate). Given that the largest inhabited Oolite planets are not much larger than Earth, and most are a fair bit smaller, that can't really be justified by catering to high-G species. (So yes, the real justification is clearly gameplay challenge)

Why spin rather than artificial? It could be a question of power consumption. Artificial gravity in a spaceship only really needs maintaining for the crew areas - the hold, engines, etc. could be kept in zero-G. So relatively little energy needs to be spent to do artificial gravity, and spaceships have a very high density of power sources.

Meanwhile a space station is very large, and they're mostly habitats which need gravity. So the ratio of power sources to gravitational space is relatively low, and rotation is a cheap way to get it.

Another possibility is that artificial gravity technology is a relatively new technology, and one that's difficult to retrofit. If you look at the in-service dates for the stations, most of them are centuries old. So, again, a spaceship might have had artificial gravity retrofitted to the crew areas - even an old Python, if one of its owners got lucky on a trading run and decided to splash out - but no-one really feels like the expense of refitting an entire cubic kilometre of space station just so they can stop it spinning. (The newer TransHab stations are mostly stationary, with just a couple of large centrifuges for scientific research)

(Oh, and welcome to the friendliest board this side of Riedquat)

[Micha]

Actually, there's nothing canon to say that ships have artificial grav; and some fanfic actually says quite the opposite! As usual, pick your favourite handwavium

[Disembodied]

Why spin rather than artificial? It could be a question of power consumption. Artificial gravity in a spaceship only really needs maintaining for the crew areas - the hold, engines, etc. could be kept in zero-G. So relatively little energy needs to be spent to do artificial gravity, and spaceships have a very high density of power sources.

Meanwhile a space station is very large, and they're mostly habitats which need gravity. So the ratio of power sources to gravitational space is relatively low, and rotation is a cheap way to get it.

This is the one that makes sense to me, personally. Spinning is a cheap way to get a range of gravities, from zero at the axis to the highest at the edge (although, as cim points out, in-game the rotation is a bit too fast and would produce very high G, but I can ignore that). Some people (and industries/storage areas) will prefer low G, others will prefer high, and this saves installing gravity generators at different settings throughout the station. Artificial gravity is (I think) produced by the ship's engines, which are large beasts, but which (as we know from mass-locking) tend to interfere with each other and don't operate optimally inside gravity wells: fine on board a ship, but not fine if you're trying to run multiple engines to produce multiple gravities in orbit around a planet.

Then you've got factors like overheating: rotating allows the station to keep its hull temperature constant, rather than having one side sit in the full glare of the sun for hours and other other in blackness. Any permanent, stationary (i.e. not zooming hither and yon like a ship) structure in space is going to have to rotate. Which raises questions about why some OXP stations don't rotate ... I'm guessing some sort of special supercooling methods and/or industrial requirements that exploit major temperature imbalances.

[Sagasa]

Then you've got factors like overheating: rotating allows the station to keep its hull temperature constant, rather than having one side sit in the full glare of the sun for hours and other other in blackness. Any permanent, stationary (i.e. not zooming hither and yon like a ship) structure in space is going to have to rotate. Which raises questions about why some OXP stations don't rotate ... I'm guessing some sort of special supercooling methods and/or industrial requirements that exploit major temperature imbalances.

Hmm... temperatures certainly would be far more extreme out in space due to the absence of a protective atmosphere so I can see why rotating the station to distribute the heat would be desirable.

I'm now led to wonder as to where the stations get their power. Solar panels perhaps? Solar energy would probably be the most readily available form of energy for a stationary object out in space and it would free them from the fuel limit that plagues smaller spacecraft. How much power could one generate with a Coriolis-sized solar panel I wonder. Would that be enough to power the station?

Why spin rather than artificial? It could be a question of power consumption. Artificial gravity in a spaceship only really needs maintaining for the crew areas - the hold, engines, etc. could be kept in zero-G. So relatively little energy needs to be spent to do artificial gravity, and spaceships have a very high density of power sources.

Meanwhile a space station is very large, and they're mostly habitats which need gravity. So the ratio of power sources to gravitational space is relatively low, and rotation is a cheap way to get it.

Another possibility is that artificial gravity technology is a relatively new technology, and one that's difficult to retrofit. If you look at the in-service dates for the stations, most of them are centuries old. So, again, a spaceship might have had artificial gravity retrofitted to the crew areas - even an old Python, if one of its owners got lucky on a trading run and decided to splash out - but no-one really feels like the expense of refitting an entire cubic kilometre of space station just so they can stop it spinning. (The newer TransHab stations are mostly stationary, with just a couple of large centrifuges for scientific research)

Ah, it seems that, even in the distant future, we still can't escape the clutches of economics...

I agree with both of your points and they're certainly a far better explanation than my own personal theory that the station engineers did it for the lulz.

As for the 10G environment that such a spin speed would produce, the Galactic Cooperative has already shown a tendency towards pragmatism with their navy reservists policy. Perhaps they're secretly attempting to transform all of their citizens into super-strong soldiers born and bred in a high G environment? It certainly would explain why the Galactic Federation and Duvall Empire are so wary of them.

[snork]

Actually, there's nothing canon to say that ships have artificial grav; and some fanfic actually says quite the opposite! As usual, pick your favourite handwavium

Artificial gravity in my ship ? How gross! No obcseneties here, please.
You one of those abominable lobsteroids of rotten morals I assume.

There is an experiment you can do to see that not only does your ship not feature artificial gravity, but rather has one of them [darn, me no good in techno-SF-babble (English version) ] thingies that won't let any acceleration affect the inside of Oolite ships.
(In German it usually are Dämpfungsgeneratoren or Stasisfeld or sth.)

Experiment goes as follows : just accept when some friendly person offers you a ship pet.
For only 30 credits. A real bargain.
And they usually make nice soothing sounds.

[Commander McLane]

There is an experiment you can do to see that not only does your ship not feature artificial gravity, but rather has one of them [darn, me no good in techno-SF-babble (English version) ] thingies that won't let any acceleration affect the inside of Oolite ships.
(In German it usually are Dämpfungsgeneratoren or Stasisfeld or sth.)

I guess inertial dampeners is the term you're looking for.

[Disembodied]

I'm now led to wonder as to where the stations get their power. Solar panels perhaps? Solar energy would probably be the most readily available form of energy for a stationary object out in space and it would free them from the fuel limit that plagues smaller spacecraft. How much power could one generate with a Coriolis-sized solar panel I wonder. Would that be enough to power the station?

Much depends I suppose on how clean and shiny/dark and grungy your personal ooniverse is ... I can see quite a lot of power being generated by fusion or even fission reactors, myself.

[Cmdr. Maegil]

Subject: Docking bay size and rotation speed

I've been researching the correct rotational speeds for space stations to generate 1G gravity.

Given a radius of approx 500m (since a Coriolis is about 1km in diameter) the rotational speed would be 1.33 rpm. Not as fast as I would have thought, oddly...

I assume that would be 1G at the outer hull, becoming less in the interior levels until we finally reach the Zero-G-cricket ground in the very centre.

So perhaps the rotation speed would be a little faster, maintaining 1G in some intermediate level, less than that on the inside, and more than that towards the hull.

For instance, the same calculator says that for 1.5 rpm you get 1.25G at 500 meters (which seems just bearable), but only 0.62G halfway down to the centre at 250 meters. In this case you would have 1G at 397 meters.

So,

- create a folder Oolite\AddOns\main_stations_slowdown.oxp\Config
- in this folder, create a file named shipdata-overrides.plist
- open it with a text editor such as jEdit or Notepad++ (NOT Notepad, it adds corrupting metadata)
- copy the following code and paste it on the file

Code: Select all

{
	"coriolis-station" =
	{
		station_roll = 0.15;
	};
	"dodecahedron-station" =
	{
		station_roll = 0.15;
	};
	"icosahedron-station" =
	{
		station_roll = 0.15;
	};
}

Save and restart with the shift pressed until the spinning ship appears.



EDIT: changed to El Viejo's suggestion

[Cody]

I reckon stations look much better with a slow roll... I use station_roll = 0.15; for mine.

[Sagasa]

@El Viejo and Cmdr. Maegil

You sirs are my heroes!

[DaddyHoggy]

I reckon stations look much better with a slow roll... I use station_roll = 0.15; for mine.

I concur - it's not about ease of docking - it's about a sense of ponderous grandness as you move into dock - odd, how the stations seem to be bigger because they're spinning more slowly...

[Cody]

it's not about ease of docking - it's about a sense of ponderous grandness as you move into dock

Absolutely! It's very good practice for new Jamesons to learn manual docking at normal station roll speeds though... those skills will be useful!

[CaptSolo]

I reckon stations look much better with a slow roll... I use station_roll = 0.15; for mine.

I concur - it's not about ease of docking - it's about a sense of ponderous grandness as you move into dock - odd, how the stations seem to be bigger because they're spinning more slowly...

I was not aware of this key. Always felt the stations were rolling too fast. Your value is more realistic. Ta El Viejo!

[Smivs]

Yup, the spin wouldn't work for gravity as the range is too broad, so I reckon artificial gravity and probably reactors for power. In my head/Ooniverse it's all to do with stabilty and centrifugal stuff.