Stomach turning transport ring in Orbis Starports

[Edith_The_Hutt]

Forgive me is this has been raised before.

After sitting in a Orbis starport for a few minutes I've noticed the interior has a set of raised roads with small cars running around the inner circumference of the station in both directions and I realized something: These cars have more (or less) gravity than the rest of the station's inner surface.

I've timed the cars and they take about 90 seconds to complete a full circle. Using the rough figure from the wiki that the docking hub is about 2 km in diameter, that comes out at 70 meters per second (or about 150 miles an hour). It works out that the cars gain or lose about 4.3m/s² or slightly less than 0.5G (These figures are literally on the back of an envelope right now but they're in the right area)

This is comparable to the gravity in the stardock, some of those cars are basically weightless and some have roughly a full gravity.

I'm not sure how this would affects the cargo, but I really wouldn't want to pull a right hand turn in one of those cars. Is this really a practical design? Surely those cars should be going a lot slower.

 

[aws357]

I always wondered what would happen if someone living in a coriolis station was to jump. Would this person still be subject to artificial gravity?

It must be a pain to play football in these station.

 

[Billy Chase]

Indeed. If you compare the speed of the trucks going backwards with the speed of the station turning. It's been a while since I did that, but at the time I found the trucks were going at exactly (!) the speed the station was turning. Meaning: They actually stood still = they were completely weightless.

It's really fun thinking about it. Let's say standing still is 1g (it isn't in game, but just for the sake of argument.) Then you push the pedal to the floor. At first you'll get down to 0g and if you continue you'll get back up to 1g and eventually 2g and more. And if you break you first get lighter and then heavier again. Talk of a roller coaster! I wanna do that!

 

[Cmdr Ig]

I always wondered what would happen if someone living in a coriolis station was to jump. Would this person still be subject to artificial gravity?

It must be a pain to play football in these station.

Jumping applies a small velocity towards the centre of rotation, but does nothing to offset the massive tangential velocity you have - so, yes, you still have "gravity", throwing you back to the floor. I've heard that playing darts is a little strange though...

 

[Surly_Badger]

I wonder what it's like to take a shower in that gravity?
I'd assume the bathrooms would be closer toward the "upper"/"inner" part of the orbital so you'd be under lower gravity, so the water would cling a bit (saves water, right?)

 

[Soda Popinski]

The station isn't completely hollow. While the whole docking hub is 2km, the interior of the hangar isn't. I'm estimating less than 1km based on the letter box being about 120m wide (2 Anacondas barely fit side by side at 60m wide).

Anacondas are 250m long. Use that as a ruler to get an idea of the interior diameter. To get 2km, you'd be able to put 8 Anacondas end to end inside.

Reminded me of this:

Spoiler

[video=youtube;9QuLgl2vKis]http://www.youtube.com/watch?v=9QuLgl2vKis[/video]

Edit: Rewatching my video, I'd have to up my estimate on the size of the letter box. easily 200m wide. Probably more. Still estimating an interior diameter of 1km.
[video=youtube;cq6s59YGVZc]http://www.youtube.com/watch?v=cq6s59YGVZc[/video]

 

[Edith_The_Hutt]

Jumping "up" in a spinning frame ought to mean you move towards the direction of spin and falling "down" means you move in the opposite of the direction of spin, this is a result of you retaining your inertia perpendicular to the axis of spin as you move toward or away from it. It also means you want to be throwing your darts parallel to the axis of spin to stop them from drifting up or down as you throw them. In other words going up pushes you spinward and going down pushes you widdershins (and vice versa).

This is extremely important when climbing a ladder on a Coriolis starport.

 

[Stavro Mueller]

I wonder what it's like to take a shower in that gravity?
I'd assume the bathrooms would be closer toward the "upper"/"inner" part of the orbital so you'd be under lower gravity, so the water would cling a bit (saves water, right?)

You wouldnt take a shower. The water would just go sideways to the person in the shower. But I guess you could build the showers so the water nearly went downwards i.e., with the floors at a (almost right) angle. Rotational gravity is not gravity, it's entirely different and would feel entirely different. It's based on centrifugal force (or, for the real hardcore physicists, anticentripetal force) and you can't imagine that you can just assimilate it, it's entirely different. You'd always sense a sideways component to the gravity, which would be seriously disconcerting for months.

 

[Edith_The_Hutt]

The station isn't completely hollow. While the whole docking hub is 2km, the interior of the hangar isn't.
<snip>
I'd have to up my estimate on the size of the letter box. easily 200m wide. Probably more. Still estimating an interior diameter of 1km.

That would help somewhat, it would cut the accelerations by half or so (and the internal speed down to about 70mph), but that's still a pretty harsh sudden change in gravity for cargo or people.

 

[EAGLE 5]

You all have way too much time on your hands.

Seriously.

 

[Surly_Badger]

You wouldnt take a shower.

No wonder stationers reek.

(Now I am thinking of Bruce Sterling's old book Schizmatrix, in which spaceships have super cockroaches that clean up skin flakes and whatnot that fall off the crew... I assume the future doesn't smell very good.)

 

[Soda Popinski]

You wouldnt take a shower. The water would just go sideways to the person in the shower.

The water wouldn't go sideways relative to the person in the shower. The water would come out of the spout already with the same sideways momentum (angular momentum?) the showerer has. As the water droplet goes in a straight line due to inertia, the showerer and the floor are pushed upward towards the droplet due to the spin of the station. So from the point of view of the showerer, the droplet is falling downward. From the point of view of the droplet, it's in freefall, and gets smacked by the floor / showerer.

Assuming there's water pressure pushing the water out, that's extra inertia it would have downward.

 

[Edith_The_Hutt]

The water wouldn't go sideways relative to the person in the shower. The water would come out of the spout already with the same sideways momentum (angular momentum?) the showerer has. As the water droplet goes in a straight line due to inertia, the showerer and the floor are pushed upward towards the droplet due to the spin of the station. So from the point of view of the showerer, the droplet is falling downward. From the point of view of the droplet, it's in freefall, and gets smacked by the floor / showerer.

Assuming there's water pressure pushing the water out, that's extra inertia it would have downward.

It would go downward and slightly anti-spinward. The shower head is spinning ever-so-slightly slower than the shower floor so it would hit slightly behind where the floor is. Admittedly in a rotating reference frame a full kilometer in radius then it's probably missing exactly down by a few millimeters at most, but it highlights the importance of an adjustable shower nozzle in space hygiene.

 

[Stavro Mueller]

It would go downward and slightly anti-spinward. The shower head is spinning ever-so-slightly slower than the shower floor so it would hit slightly behind where the floor is. Admittedly in a rotating reference frame a full kilometer in radius then it's probably missing exactly down by a few millimeters at most, but it highlights the importance of an adjustable shower nozzle in space hygiene.

The 'ever-so-slightly' is irrelevant. Once the water is out of the showerhead, there's nothing pushing it sideways. The higher the water pressure, the further it'll get in its own frame of reference, so the closer to straight out, but the apparent sideways motion (Coriolis effect?) will always be a huge factor, even more so the bigger the space station, as the sideways velocity will be bigger as the radius increases.

- - - Updated - - -

The water wouldn't go sideways relative to the person in the shower. The water would come out of the spout already with the same sideways momentum (angular momentum?) the showerer has. As the water droplet goes in a straight line due to inertia, the showerer and the floor are pushed upward towards the droplet due to the spin of the station. So from the point of view of the showerer, the droplet is falling downward. From the point of view of the droplet, it's in freefall, and gets smacked by the floor / showerer.

Assuming there's water pressure pushing the water out, that's extra inertia it would have downward.

This isn't true; it's not _real_ sideways momentum, it just seems like it. There's no sideways momentum because the vector of motion is constantly changing. That is to say, angular momentum only exists for rigid bodies, because they hold together and provide the necessary centripetal force.

__

Imagine it for a minute. What's the difference between this and swinging a hose round your head?

 

[Deleted member 38366]

--- Deleted ---

 

[Stavro Mueller]

Since these cars seem to be robotic in nature and on magnetic tracks (or comparable) - I don't think they actually need the gravity to transport their goods

PS.
Rumor has it that these vehicles are actually counterweights that fine-tune the Station's rotation, as well as contain high-sensitivity gravimeters; effectively counteracting any docking or departing Ship masses by modifying their speed and number of Vehicles going both ways as needed.

Apparently this was implemented after some of the Prototype Stations of the Coriolis Design nearly went out-of-control and suffered structural damage from asymmetric rotation deceleration after multiple heavy Type-9's landed within a single Segment in short succession.

omg. I've just thought through this, and it's not negligible (is anything really negligible in space?). The station would need to be constantly adjusting its trim to maintain a uniform rotation. FD, we need to see thrusters on station exteriors.

Edit

That said, its orbit would not need adjusting very often. In fact, if I was a station commander, I wouldn't bother until it got important. FD, we need stations with rotational eccentricities.

 

[Deleted member 38366]

--- Deleted ---

 

[Edith_The_Hutt]

It gets worse. Those stations are going to flex as they spin with asymmetrical mass; the ones built about a single axial spine will probably have it worse as a shell design (Coriolis) has more material holding the structure together and is almost certainly more rigid.

I'd guess that either all stations have a dynamic counterweight/off-axis rotation systems to prevent them from shaking themselves apart or they have a thruster system to adjust the load and account for precession. Either way I reckon the central spines of the Orbis and Occelus starports have to be built with flexibility built in, otherwise you're just begging for metal fatigue in those sections.

 

[COOPER TTE]

@this entire thread and the many many similar types - haha I just love you guys and this community

Not many games where the forumites spend this much time and effort postulating, musing, calculating and theorizing just for kicks (when not engaged in fearful sibling-level animosity of course!)

It adds so much to the game universe. Keep it up and long live !SCIENCE!

 

[Jon474]

I love this thread.

For a manufacture and operator of space stations the balance must be made between the comfort of the residential population as well as the business-end bit...space ship traffic. I would expect that the handling of gains and losses in mass caused by the docking and undocking of traffic would merely have to be a "fine-tuning" event because in order to make it all remotely achievable surely the vast proportion of the permanent mass must be in the body of the space station itself and not solely in the ship docking related areas of the station. I see a careful control over the arrival/departure schedule and the loading/unloading of mass onto the appropriate area of the deck as being important but not so critical that the stability of the station becomes compromised by any imbalance. The greater mass contained in the station dampens most of the effects of imbalance and thus only fine-tuning for an unexpected loading event is required.

What about the mass of ships within the station but not docked? Any impact?

Flying happy

Jon