PLEASE stop the way space stations ROTATE

[who?]

I'll explain the problem - because it is an interesting one:

1. the stations rotate, deliberately, and quite rapidly, in order to provide artificial gravity.
2. there's a requirement in game that the slot faces the planet - not sure why! But that's sci-fi
3. if the station rotates about that central axis, it can represent a vector, if you wish, which is locked directionally along that axis - not by standard linear inertia, but by angular momentum.
4. As the station orbits, if that slot is to remain facing the planet, that axis / vector must rotate to keep pointing at the planet
(folks have been calling that 'precession' - but it is a total misuse of the term - oops - hence the controversy - but that aside - not important here
5. If that vector has to keep pointing inward to the planet, and rotated, a torque (turning effect) *has* to be applied by the space station.
6. That's about it - if the space station wants to rotate *in that manner*, and *still* have the slot facing the planet, there need to be thrusters firing.

That's the essence of it.

So, the space station's orbit - in that attitude - has to be *maintained* - with energy expenditure - it's not inertial.

Hope that helps.

(OK, an orbit is not strictly inertial - but the sense is clear enough I hope.)

Ah, thanks for the explanation. A few points:

1. Landing pads have "Caution Zero Gravity" and "Warning Low Gravity" warnings on them. This implies some kind of localised gravitation fields are possible in the Elite universe. The stations might not need to rotate in order to generate gravity, but it might be more efficient to do so, or else it's just for effect, making landing more interesting

2. I guess it kind-of makes sense, in that you'd expect most traffic to be to-from the surface. I don't know if there's any safety reason to having the dock facing away from any potential hazards (such as solar wind, or dozy pilots supercruising into the slot). However, not all docks face the planet, some have quite different orientations.

But ultimately 6: yes, that's what I thought. I didn't/don't have the smarts to work out if a station could spin on that axis while also being gravitationally locked, but I can't see why it wouldn't be possible with thrusters. Energy usage / efficiency doesn't seem to be a concern in the Elite universe!

 

[Zieman]

1. Landing pads have "Caution Zero Gravity" and "Warning Low Gravity" warnings on them. This implies some kind of localised gravitation fields are possible in the Elite universe. The stations might not need to rotate in order to generate gravity, but it might be more efficient to do so, or else it's just for effect, making landing more interesting

Nope. In Elite: Dangerous universe humans do not possess the technology to manipulate localised gravitation fields.

The landing pads have low gravity in rotating stations because they're so close to the axis of rotation. IIRC it is supposed to be about 1/10 of the gravity on Earth. At the outer edge of station the gravitational effect is about equal to Earth surface gravity.

On various outposts the landing pads indeed are in zero-g. They use magnetic clamps to attach the ship to them.

 

[Bran Tse Mallory]

I'm afraid it wouldn't help. Even with contra-rotating gyroscopes, the net angular momentum would just be the sum of the two; which could be zero. There are no ways around some of these basic problems.

Time to put a stop to a circular argument... Space Fan, this is 1000 years from now. The technology they have would appear to be like magic to you and I. They have found a way to make the stations rotate in the way they do. That's all you and I could ever hope to understand as our brains are just not evolved enough to understand the concept of the technologies involved or the advances in the laws of physics that have been made.

 

[Kigre]

I can't stand it anymore. It makes me cringe everytime I drop out of SC and see a station.
THIS DOESN'T WORK!!!

You can't have space stations rotate like they do AND have the entrance point in the general direction of the planet they're orbiting.

It will not work! The entrance will be, after half an orbit, opposite of the planet.
Which would, by the way, not change a thing as when you drop out of SC it's always a gamble where the entrance is - it definitely is NEVER where you expect it.



Solution is simple:
Have them rotate perpendicular to their orbit plane.
And please, for heaven's sake, add a second entrance. Lots of problems solved (except for occasional drafts of space winds with two doors open..).

"It will not work!" But it is working!!!? I get into the station everytime. It works like a charm.

 

[Whiterose]

Not as irritating as the feedback you get from station announcements. The year is 3301 and we still have dodgy tannoy systems.

 

[Soopyyy]

Stations have thrusters, they keep themselves aligned. Job done.

 

[TriumphANT]

By far, and I mean by far the biggest issue with a rotating station is that docking as it's perceived in the game would be nearly impossible. You cannot have "rotation lock" once you're off the central axis. Your ship would need to continually side-thrust, assuming its attitude was perfectly aligned to the chord of the axis of rotation. If you roll or pitch your ship, it won't be able to correct its position perfectly, and there's no indication that our ships side-thrust during landing in stations.

As a thought experiment, imagine having a penny on a stick inside the drum of a slowly rotation washing machine and trying to get it to touch the washing machine drum without relative motion. You need to keep spinning the stick around, and the further from the axis, i.e. the closer to the drum, that you get, the more absolute motion is required.

2001: A Space Odyssey had it exactly right. You move into the centre, and land in the centre with rotation matched.

The OP is basically correct though. A rotating station would never be able to keep its face towards the planet. It's OK saying you could counteract the angular momentum with gyroscopes, but the forces involved are massive, and an Anaconda landing would send the thing off into gyroscopic hell.

 

[CMDR Crustatious Cornelius Pig]

I can't stand it anymore. It makes me cringe everytime I drop out of SC and see a station.
THIS DOESN'T WORK!!!

You can't have space stations rotate like they do AND have the entrance point in the general direction of the planet they're orbiting.

It will not work! The entrance will be, after half an orbit, opposite of the planet.
Which would, by the way, not change a thing as when you drop out of SC it's always a gamble where the entrance is - it definitely is NEVER where you expect it.



Solution is simple:
Have them rotate perpendicular to their orbit plane.
And please, for heaven's sake, add a second entrance. Lots of problems solved (except for occasional drafts of space winds with two doors open..).

I see your issue but I don't think it matters to me. I'm fine with the mechanics as they stand.

 

[Apos]

By far, and I mean by far the biggest issue with a rotating station is that docking as it's perceived in the game would be nearly impossible. You cannot have "rotation lock" once you're off the central axis. Your ship would need to continually side-thrust, assuming its attitude was perfectly aligned to the chord of the axis of rotation. If you roll or pitch your ship, it won't be able to correct its position perfectly, and there's no indication that our ships side-thrust during landing in stations.

As a thought experiment, imagine having a penny on a stick inside the drum of a slowly rotation washing machine and trying to get it to touch the washing machine drum without relative motion. You need to keep spinning the stick around, and the further from the axis, i.e. the closer to the drum, that you get, the more absolute motion is required.

2001: A Space Odyssey had it exactly right. You move into the centre, and land in the centre with rotation matched.

The OP is basically correct though. A rotating station would never be able to keep its face towards the planet. It's OK saying you could counteract the angular momentum with gyroscopes, but the forces involved are massive, and an Anaconda landing would send the thing off into gyroscopic hell.

Calling a force "massive" only matters when you are limited by the power required to invoke it though.

Hydrogen fusion laughs at what is today called massive in terms of power expenditure and applicable forces as a result.

 

[TriumphANT]

Calling a force "massive" only matters when you are limited by the power required to invoke it though.

Hydrogen fusion laughs at what is today called massive in terms of power expenditure and applicable forces as a result.

Anyway, it's just a game. But overcoming the kind of forces involved in "pushing" a spinning object around its axis of rotationg would be genuinely impossible, no matter what the power source is. Using some form of counter-rotating gyroscope helps obviously.

Game. Game. Game. Stop me from getting upset by physics.

 

[bootsam]

This is such a non issue. Firstly, its a game and not real. Secondly the yr is 3301 and new technologies and techniques will be around. Thirdly, the elephant in the room and it isnt the T9.

The elephant is the fact that there is one slot to both enter and exit. Instead of a slot to enter and one opposite to exit. This would also remove the need for the dock to turn you. Have the space architects of 3301 gotten no better than the dimwitted arty halfwits currently practising architecture? An engineer would place one at either end for practical and logistical reasons.

Most present day architects wouldn't know a moment of inertia if you booted him up the bum to demonstrate it. Thats why they employ structural engineers. To do the hard bit with sums and leave them alone with their crayons and chintz cushions. Architects these days are just managers who can draw a bit. Hopefully by the yr 3301 things might have improved.

 

[Lupin]

You can't have space stations rotate like they do AND have the entrance point in the general direction of the planet they're orbiting.

We would have real problem if this applied to satellite in our orbit.

Rotation in stations was for gravity and not related to orbit or location. But then again I am no scientist

 

[TriumphANT]

We would have real problem if this applied to satellite in our orbit.

Rotation in stations was for gravity and not related to orbit or location. But then again I am no scientist

Satellites rotate around their axis AND around the Earth on the same axis at a rate of one rotation per day. The ED space stations rotate around their own axis perpendicular to the axis of rotation of the planet. If you were going to build a rotating space station, you'd make the entrance point "up" or "down" parallel to the axis of rotation around the planet. Of course, if you had two doors, then the approach would be dead easy, as the doors would always line up with the rotational axis of the station around the planet.

 

[norty303]

Whole thread tl;dr

I always saw it like this.... skip to 4:25 or thereabouts...

[video=youtube;cquvA_IpEsA]https://www.youtube.com/watch?v=cquvA_IpEsA[/video]

 

[Robert Maynard]

An engineer would place one at either end for practical and logistical reasons.

.... and may choose to only fit one on cost and security grounds - the atmospheric retention system employed by the docking tube may not be cheap and one at each end would encourage drive-through attacks....

 

[robbyp]

The stations must apply small thrustings to keep them pointed at the planet. A set of thrusters on the tip and tail of the station would do it - just fire them for a short duration at the right time (when they pass thru the plane of the stations orbit) and perpendicular to the axis of the rotation.

Good point Sir!

 

[c64orinoco]

Most present day architects wouldn't know a moment of inertia if you booted him up the bum to demonstrate it. Thats why they employ structural engineers.

I employ Structural Engineers to wash my car. Some architects DO actually know some physics you know!

Just kidding about the car though, some of my best friends are engineers.

 

[Snafu Manchu]

TL;DR

Has anyone mentioned the phenomenon of tidal locking yet?

 

[TriumphANT]

The stations must apply small thrustings to keep them pointed at the planet. A set of thrusters on the tip and tail of the station would do it - just fire them for a short duration at the right time (when they pass thru the plane of the stations orbit) and perpendicular to the axis of the rotation.

Good point Sir!

Sadly, precession would mean that the station would rotate at right-angles to the angle of force too, i.e. if you're looking at the front, you'd push the "back" to the right, and it would also go "down" assuming clockwise rotation. So, you'd attempt to thrust upwards at the back? Then the original force would be countered. Increase one force and you have to increase the other. Gyroscopes are basically weird!

But... it's still just a game. Look at it this way, we don't need to worry about gravity, we don't need to worry about rotational correction, and our ammo which punches holes in military armour doesn't weigh anything. Let's enjoy the game, and ignore the physics lest we go batty. Oh. Wait.

 

[Blastbeats]

Whole thread tl;dr

I always saw it like this.... skip to 4:25 or thereabouts...

https://www.youtube.com/watch?v=cquvA_IpEsA

You forgot to /micdrop