How can i calculate geostationary orbit

[mickygom]

am using Remote tech2 mod and Real Solar System mod

and now i want sending a radio satellite on the geostationary orbit

i found geostationary orbit of original kerbin in Wiki but i don't know how changed geostationary orbit in RRS mod

1. How can i know geostationary orbit (used RRS mod.)

2. If add on be calculated geostationary orbit, what add on can this?

[CaptainKipard]

First you need to know the sidereel rotation period of the planet(T), the mass of the planet(M), and the gravitational constant of the universe(G) I don't know if it's the same as in vanilla, so you need to find out.

From the rotational period you can work out the SMA(a).

T=2*PI*(a^3/(G*M))^0.5

Then get your apses by taking away the equatorial radius from the SMA.

Edited March 21, 2014 by Cpt. Kipard

[brooklyn666]

It's the same as in real life. RSS uses all real-world figures.

[mickygom]

ya I know, and i can found geostationary orbit of earth very easily but could't find another planet

[sjwt]

ya I know, and i can found geostationary orbit of earth very easily but could't find another planet

If your not after doing the maths, the wiki has all the answers, just go there and pick your plant of choice!

http://wiki.kerbalspaceprogram.com/wiki/Main_Page

[Kasuha]

Not all planets in KSP have stationary orbits. Many of them rotate so slow that the orbit falls outside its SOI.

[Respawn]

Orbital r = cuberoot( (t² x GM)/4pi² )

To use this formula to get a Synchronous orbit you need to know the mass of the planet, and how long a day is for that planet.

t is in seconds, so if your planet rotates once every 6 hours, that's 21600 sec

GM is Newtons gravitational constant times the mass of the planet.

Not knowing how this changes with RSS i'll show you using the stock numbers.

Kerbin GM would be roughly 6.67384x10-¹¹ x 5.2915793x10²² = 3.531515x10¹²

multiplying (t²) 21600² sec with (GM) 3.531515x10¹² and deviding this number by 4pi²

and then take the cuberoot of that number you'll have your orbital radius. (3468722.89m)

now if you want the orbital altidude simply subtract the planets radius to get your number.

(in my case: 3468722.89m - 600000m = 2868722m) probbably a coupple meters off due to rounding errors.

[Kryxal]

Do note that you may be given GM directly, no reason to calculate it if it's given...

[Respawn]

well..

Just downloaded the RSS mod an hour ago to check it out for my self.

Stationary orbit is at about 35,777,650 m altitude if you still wanna know.

Holy crap, the dv requirements is just silly with this mod.

built a craft with 12500 dv, and spent it all just to get to stationary orbit to double check my result.

Edit:

In RSS:

Kerbin / (Earth analog)

rotational period: 86164.0916 sec

radius: 6371000 m

GM: 3.98161x10^14

Edited March 21, 2014 by Respawn

[Captain_Party]

This is a bit of a stupid question. RSS re sizes Kerbin to be the exact same size as Earth, as it is said on the mod page more than once. Therefore, it should (GEO) be the same height as Earths GEO height. Which is 35,786 km, or a SMA of 42,164 km.

[LordOfTheOrbits]

If you use mechjeb or kerbal engineer, just open your orbit info display and try to get a near circular orbit at about 35,786km height with an orbital period of exactly 23 hours, 56 minutes and 4 seconds.

[mickygom]

Thank you for answer for me i'm very happy

but i don't know,how can i change title 'Answered'

[TheDarkStar]

Make sure that you remember to subtract Kerbin's radius when you set up the orbit, though, since the game displays height above sea level and not distance from the center of mass.

[Randy]

On a KSP video I watch once. The person said that Kerban Geo orbit is 2,869,000 meters. I put a satellite at that altitude and it did seem to stay in place. The game crashed and I had to reload it so I could not track it for a long period of time.