KEOstationary Orbit

[Monarchco]

ok...

So this is just an observation of mine, but either kerbin does NOT have an peroid of 6 hours, OR, 2868.33km isn't keostationary.

In order to get a nearly perfect 6 hour orbital peroid, I have to place a vehicle around 2868.75km circular.

Right now I've got one satellite I managed to get up there that has an orbital peroid of 06h00m00.03s And it's just about exactly 2868.75

So I can only conclude that either:
2868.75 is keostationary, NOT 2868.33 like the ingame missions & the wiki says
OR
Kerbin doesn't have a 6 hour peroid.

[Jupiter3927]

Kerbin rotates once every 5 hours 54 minutes or so.
You can get the rotation periods of any planet from the map screen or tracking station and clicking the planet and openning the info tab.
All the data you could need and some you don't need is displayed there.

The formulas for orbital radii finding are...

T = ((4*Pi^2*R^3)/(G*m))^(1/2)
R = ((G*m*T^2)/(4*Pi^2))^(1/3)

T is your orbital period in seconds.
Pi is Pi and your calculator should have a button for this.
R is radius in meters measured from the center of the orbit, NOT from the surface of the planet.
G is newtons gravitational constant. It's about 6.67*10^-11 but you don't need it for this.
m is the mass of your planet.
G and m are refered to as Mu and this value is given to you in the game where all the other planetary information is on the map screen.

[Monarchco]

Originally posted by Jupiter3927:

Kerbin rotates once every 5 hours 54 minutes or so.

I was under the impression it was a 6 hour interval. Thanks for the clarification

[RoofCat]

Kerbin day is 6h.
1 full Kerbin rotation around its axis isn't.

You have to keep in mind Kerbin not just rotates around its own axis. It also moves on solar orbit all the time. Which makes the Sun "move" along too. And since that extra Sun time moves counterclockwise (with the Kerbin rotation), it extends the daylight and night time by a few minutes every day compared to one exact Kerbin rotation around its own axis.


The same is true for Earth. While we have 24h clocks for light reasons, our home actually does full circle form A to A in less than that (my guess by ~1 / 365.24 from 24h).

[Trixi]

Well. A kerbal day is exactly 6:00:00 hours. You have to calculate in that kerbal also orbits kerbol. So a Rotation around itself is slighlty Shorter.

The same counts for earth too. A solar day is 24:00:00 while the rotation period relative to the stars is just 23:56:04.09 hours

[Azunai]

if you're interested in that topic, read up on the difference between sidereal time and solar time (for example here: https://en.wikipedia.org/wiki/Sidereal_time#Definition )

as the wikipedia article explains, a sidereal day on earth is ~23 hours 56 minutes rather than the 24 hours of a solar day

[Astronaut]

you're correct. if you go to the tracking station to view kerbin's info, its 6 hour day is less than 6 h. same with earth. Also while still on the ground if you click the speed display a few times surface speed will be 175 m/s. Kerbin rotates at that speed. so a satellite in geostationary orbit has to travel faster than the ground because it is higher up and has to cover more distance at the same time. also the sun's equator travels faster than its poles when rotating (kerbol and sun rotate too.) and it does not split up into sections while doing so. This is not true in KSP, but the sun itself and all the planets orbit a common center of gravity at the center of the solar system.


KSP really has to start implementing some of these. And the sun's orbit around that center is really tiny.

[Chibbity]

Originally posted by camichint:

This is not true in KSP, but the sun itself and all the planets orbit a common center of gravity at the center of the solar system.

KSP really has to start implementing some of these. And the sun's orbit around that center is really tiny.

Your talking about simulating real N-body physics? That would take an entire re-write of the KSP physics engine. (Not to mention melt the majority of CPU's)

I wouldn't hold your breath, maybe in KSP 2.

[Astronaut]

Originally posted by Chibbity:

Originally posted by camichint:

This is not true in KSP, but the sun itself and all the planets orbit a common center of gravity at the center of the solar system.

KSP really has to start implementing some of these. And the sun's orbit around that center is really tiny.

Your talking about simulating real N-body physics? That would take an entire re-write of the KSP physics engine. (Not to mention melt the majority of CPU's)

I wouldn't hold your breath, maybe in KSP 2.

Well, it could happen.

[Chibbity]

Originally posted by camichint:

Originally posted by Chibbity:

Your talking about simulating real N-body physics? That would take an entire re-write of the KSP physics engine. (Not to mention melt the majority of CPU's)

I wouldn't hold your breath, maybe in KSP 2.

Well, it could happen.

Sure, anything could happen.

On a side note; if you are interested in N-body physics, I've got a great game recommendation for you:
http://store.steampowered.com/app/230290/Universe_Sandbox/

[Astronaut]

Originally posted by Chibbity:

Originally posted by camichint:

Well, it could happen.

Sure, anything could happen.

On a side note; if you are interested in N-body physics, I've got a great game recommendation for you:
http://store.steampowered.com/app/230290/Universe_Sandbox/

That's exactly the game I associate with N-body physics