Mun & Minmus: Impossible Stationary Orbits

[MitBalkens]

I am aware of the fact that both Mun's and Minmus' stationary orbits are outside of their spheres of influence. So I was wondering if anyone had any ideas as how to artificially generate such an orbit (i.e. a giant chain attached to a satellite and the Mun's surface), becuase I'm at a loss for ideas unfortunately.

[EdFred]

Well, for the Mun since it is tidally locked with Kerbin, you could put a ship just ahead, or just behind the Mun at the same orbit, and it would always remain stationary in regards to Mun.

[Tex_NL]

However it has to be in EXACTLY the same orbit. If you put an object following Mun even a little too high it will eventually lag behind. A little too low and it will catch up and enter Mun's SOI.

[cantab]

However it has to be in EXACTLY the same orbit. If you put an object following Mun even a little too high it will eventually lag behind. A little too low and it will catch up and enter Mun's SOI.

Does it not rather simply need the same orbital period? The more precise the period the less drift there will be, while a little eccentricity will just make the ship appear to librate.

[Rodyle]

I am aware of the fact that both Mun's and Minmus' stationary orbits are outside of their spheres of influence. So I was wondering if anyone had any ideas as how to artificially generate such an orbit (i.e. a giant chain attached to a satellite and the Mun's surface), becuase I'm at a loss for ideas unfortunately.

I think real life gives the solution. It's also impossible to put satellites in a stationary orbit around high-latitude regions. What if we do something somewhat like highly elliptical orbits and place two or three satellites in a semi-synchronous orbit? If done right, these would be nigh-stationary above the surface for a decent amount of time in their orbit.

[EdFred]

You can tweak the orbit with RCS, to get it almost exact. And even if it's not dead on perfect, as long as the orbital periods are the same it wont get captured, provided you don't put it 10 meters outside the SOI.

[Tex_NL]

Does it not rather simply need the same orbital period? The more precise the period the less drift there will be, while a little eccentricity will just make the ship appear to librate.

You are correct. I should indeed have said exactly the same orbital period. The exact AP, PE and inclination are not that important. The closer the better as long as your period is exactly one Munth.

[Red Iron Crown]

No one has mentioned that the chain from Mun synchronous orbit and the Mun's surface will not work. Individual craft cannot be larger than the 2.5 km physics bubble, and if it's made of smaller ships linked like chain they will pass through each other once on rails.

[SolarLiner]

Does it not rather simply need the same orbital period? The more precise the period the less drift there will be, while a little eccentricity will just make the ship appear to librate.

No, because if you want to achieve geosynchronous you need not to move relatively to the planet's surface. This is why for Earth/Kerbin, you need to have 0 equatorial inclination. Here with the Mun, you'd need to be in the same orbital plane, and have the exact same AP and PE, else you will do a sort of "pendulum move" relatively to the surface.

But anyway such an orbit is useless because of Kerbin.

[BudgetHedgehog]

No, because if you want to achieve geosynchronous you need not to move relatively to the planet's surface.

The word you're looking for is geostationary. Geosynchronous is an orbit with a period of exactly one sidereal day - geostationary orbits are a type of geosynchronous orbits and have zero inclination and eccentricity. Other examples of geosynchronous orbits include Molniya and Tundra orbits.

[cantab]

Molniya orbits are semi-synchronous - period half that of the planet's rotation - not synchronous.

[BudgetHedgehog]

Still synchronous, though. Passes over the same point on the surface at the same time each orbit.

[Red Iron Crown]

Still synchronous, though. Passes over the same point on the surface at the same time each orbit.

Almost. It passes over the same spot at the same time in each sidereal day. Where it is at a given time in the orbit alternates between two points (for 2:1 synchronicity).

[Claw]

Well, while the debate of orbit names is an important detail, I think it might be clouding the OP's question.

...Mun's and Minmus' stationary orbits... So I was wondering if anyone had any ideas as how to artificially generate such an orbit...

Perhaps we should ask what you are trying to accomplish. Perhaps knowing that will help us come up with alternate solutions.

I understand that you are asking about stationary orbits, but to what end? Perhaps there is another way to accomplish your goal.

[UmbralRaptor]

As others have mentioned, you can fake a stationary orbit by sticking a craft in the same orbit as the Mun but just outside its SOI.

I am aware of the fact that both Mun's and Minmus' stationary orbits are outside of their spheres of influence.

Stationary orbits for Minmus have been inside its SOI since 0.17.

[GoSlash27]

I am aware of the fact that both Mun's and Minmus' stationary orbits are outside of their spheres of influence. So I was wondering if anyone had any ideas as how to artificially generate such an orbit (i.e. a giant chain attached to a satellite and the Mun's surface), becuase I'm at a loss for ideas unfortunately.

Beyond what's been suggested already, you could simply place your "satellite" on one of Kerbin's poles...

[MitBalkens]

Haha, it was simply a joke. The chain part that is.

Edited July 1, 2014 by MitBalkens

[MitBalkens]

Hm.. but if i match mun's orbit ill only be able to orbit two points of the moon. Not the inside or outside parts.

Edited July 2, 2014 by MitBalkens

[Claw]

What is it that you are trying to do with the stationary orbits?

[Lanzecki]

€10 says he's using RemoteTech 2 and trying to get a fulltime satellite link to the Mun without getting stupid on the amount of satellites and links.

I did the same and tried getting a satellite on the same orbital period and in front of the Mun. More then possible, but don't scrimp on the antenna and use the short range ones.

There are YT video's about it. Search for Lanzecki. I did a whole series of Vid's using RremoteTech

[velve]

Probably remotetech2, I have managed to get a full time connection to the Mun using 3 satellites. Polar orbit, equatorial and something around the 45 degree mark. At various heights and speeds so I guess you don't need so many satellites, or the hassle of trying to get a geostationary orbit.