How do we know the rotation of Kerbin? (or the other bodies?)

[workmaster2n]

After reading a bunch of tutorials, it seems to be the general consensus that Kerbin, like Earth, has an easterly rotation and that's why we rotate to the east to achieve orbit. I've looked around, but haven't found any documentation pointing out how we know this to be the case. Are the rotations of the bodies noted somewhere or is just by trial and error?

Thanks

Edited October 1, 2013 by workmaster2n

[Kerbolnaut]

The easiest way to verify it is to sit on the launchpad, and, instead of launching, just accelerate time. You'll see the sun rise in the east and set in the west. Since the sun appears to be moving from east to west, and since that's due to planetary rotation rather than orbiting (which you can verify if you go out into map mode while you're accelerating time) you can verify that the planet is rotating towards the east.

[Araym]

If you use ISAMap mod, it has a nice "kerbalpedia" feature showing you all the most importan planets/moons features...

... but if you don't, http://wiki.kerbalspaceprogram.com/wiki/Main_Page <-- Kerbal Wiki is your friend.

Just open the main page and click on planets/moons images to redirect you in nice pages full of datas about orbits, orbital periods, inclinations and so on... ;-)

[Skorpychan]

Go to the map view and watch the planet rotate while time-accelerated.

[workmaster2n]

I searched the documentation but didn't see anything about rotation direction. Is one of the descriptors here: http://wiki.kerbalspaceprogram.com/wiki/Kerbin a description of the spin direction?

[Vector]

Sidereal rotation period determines the speed of rotation but direction is implicit. All planets and bodies rotate about the same axis and all rotate to the east. None have an inclined axis of rotation or rotate to the west.

Edit: nearest thing I know of to actual documentation is this: http://forum.kerbalspaceprogram.com/threads/45519 wherein someone claimed "Unity does not support tilted planets." (not sure if I believe it, but it was claimed).

Edited September 23, 2013 by Vector

[sopwerdna]

...someone claimed "Unity does not support tilted planets." (not sure if I believe it, but it was claimed).

While I don't know much about Unity, I'm pretty sure that planets are not part of Unity but rather part of Squad's programming... and also that if any game engine did not support tilting models in game environments, nobody would ever use it.

[Kulebron]

When standing on the launchpad click on the navball title "Surface" and switch it to orbit view. It will show you the orbital speed, 176 m/s. This is the equatorial rotation speed of Kerbin.

Many moons are tidally locked (Mün, Laythe for instance).

[AlamoVampire]

In the pictures below, I have the capsule aligned so North <red line on the nav ball> is to the hatch's RIGHT, and East is directly to the capsules Back side. Also in picture 1, I have it aligned so the Navball shows my back is facing a heading of 090 or directly EAST. I then pointed the capsule's top as close to East and 090 as I could, but, its round, it rolled and landed a few degrees off to a heading of 093.

I should also point out, that, using those 2 pictures, you can translate that into first map view of Kerbin itself, then expand out and watch it go along its orbital path, which is anti-clockwise around Kerbol, which, is identical to how Earth goes around the Sun, as do the other bodies in the game. Its why orbital mechanics in KSP work, they are following real world rather closely.

Edited September 24, 2013 by AlamoVampire

[Vector]

While I don't know much about Unity, I'm pretty sure that planets are not part of Unity but rather part of Squad's programming... and also that if any game engine did not support tilting models in game environments, nobody would ever use it.

Right, this is why I am skeptical of the claim. But separate from whether planets could be inclined, I believe they are not.

[sopwerdna]

No, Vector, it seems to me as if no planets are inclined...

[BubbaWilkins]

It's likely a design choice to allow for more accessible gameplay. Just think for a second how much DeltaV and in game time would be wasted trying to match planetary orbit inclinations if they weren't already on the same plane? At least now you have at least one optimal transfer position each orbit. Imagine having to wait 10-100-1000 years for that one chance to get to another planet because it's inclination and orbital period only come in range once in those time periods.

[AlamoVampire]

Isnt Eeloo on a different plane or is that just my copy of the game?