Space Station in an eccentric Kerbol orbit?

[Burke112]

While thinking about interesting locations to place space stations, and the idea of putting a station in a highly eccentric orbit around Kerbol, with an apoapsis just outside of Eeloo's orbit and a periapsis closer to Kerbol than Moho, seemed intriguing. What I'm wondering is, would such a station be viable, or would unplanned encounters with other planets, and the gravity assists/brakes that the encounters caused, occur often enough to skew the station's orbit?

[Echostatic]

Even if you did somehow encounter a planet, if you aren't actively controlling the space station, physics will not apply and it will remain unaffected.

[Mic_n]

throw it in a polar orbit and you avoid the SOIs of those other planets.

Biggest thing is.. for what purpose? If you're going to dock with it, you still need to match orbits so that your relative velocity lines up. You also have very narrow windows..

So yea, it's certainly possible to put it in an orbit as you describe... but why would you?

[Mic_n]

plus what he said. unless it's focused the sim remains 'on rails' and those interactions (captures/aerobraking/etc) don't happen.

[inigma]

What is the purpose of such a space station outside your normal space lanes, if not to house your most dangerous space criminals? Fried one too many Kerbals, eh? Followed in Danny's lead, eh?

[Burke112]

Yeah, I guess I had a bit of a stupid moment there and forgot about the simulation being on rails.

I'm not sure exactly what purpose such a base would have, except for being very unusual...

[TooManyErrors]

I'm not sure exactly what purpose such a base would have, except for being very unusual...

Studying Kerbol's poles and solar (Kerbolar?) wind?

[AustralianFries]

Studying the Sun's atmosphere and surface.

[Burke112]

Well, if Kerbolar (like the term!) research was its purpose, it wouldn't have to be in an eccentric orbit...

I guess it could serve as a refueling depot for interstellar travel, if that is ever implemented. I think interstellar travel in KSP is supposed to use a FTL drive, though, so I'm not sure if that would be useful...

I have the life support mod installed as well, so I have to keep my Kerballed stations stocked with regular shipments of food (water, oxygen, and CO2 removal are all taken care of by self-sufficient onboard systems)... so what kinds of launch windows could one expect for intercepting a space station in an eccentric Kerbol orbit, in terms of how wide/narrow they are?

[maackey]

Physics might not apply when "on rails" but objects in space do get affected by changing SOI's. I just had a craft break apart when trying to separate from the main (empty) lifting stage carrying my ship to the Mun. Some parts got blasted far enough away to stay in Kerbin Orbit, some parts hit the mun (and were subsequently destroyed), and others flew off into interplanetary space. I dunno whether it was because I was relatively close to the debris, but I was definitely outside 5km.

[Johno]

A real life concept is the idea of a space station on a cyclic orbit between Earth and Mars (with capsules that can ascend from Earth, dock with the cycler, then descend on Mars etc). However I don't think the physics model for KSP is sufficiently complex to model orbits of this kind.

[PolecatEZ]

Its not a particularly hard thing for the game to do, the problem is you have to do all the math and timing by hand to make it work. So far, nobody has released a mod that calculates waypoints for starting up your Aldrin cycler.

[Tiron]

Watch someone do this and have their station just flat-out disappear because it somehow got within the despawn-unfocused-objects threshold of a planet (20km on Kerbin, I don't know if it varies).

[Frederf]

23km on Kerbin which I believe is some function of the atmospheric scale height.

[mellojoe]

Would the energy required to dock with an elliptical orbiter be the same as required to reach that same elliptical orbit?

meaning, does it save you any fuel?

[Khrissetti]

A little more, I'd imagine, to do all the correction burns you'd need to do.

[Lexif]

Even if you did somehow encounter a planet, if you aren't actively controlling the space station, physics will not apply and it will remain unaffected.

That's wrong, gravitational interaction will be modelled as far as I know. For example, my mun rocket once left a piece of debris in a highly excentric Kerbin orbit. After a few months, I noticed it had ended up in a solar orbit. I guess a mün encounter ejected it out of Kerbin's sphere of influence.

[PolecatEZ]

It saves you fuel because the relay ship/shuttle is very small, while the cycler is very large and equipped for long trips. In real life, this is a massive "mass" difference, which translates to a lot of fuel savings for manned trips.

[TaranisElsu]

Encounters and SOI changes can definitely happen to unfocused ships. I've had two things happen: (1) a satellite in Kerbin orbit matching the Mun's orbit and a little behind it, just outside the SOI, ended being captured by the Mun and then ejected into an eccentric orbit, and (2) a satellite just inside Mun's SOI, around 2000 km, got ejected from Mun's orbit and ended up in a Kerbin orbit.

And as PolecatEZ said, the advantage of an Aldrin Cycler (or Mars Cycler, http://en.wikipedia.org/wiki/Mars_cycler) is that your shuttle to/from Earth's surface and to/from Mars' surface can be quite small, while the cycler has everything you need for interplanetary travel. The dV requirements to dock with the cycler are the same, but the smaller mass of the shuttle means that you do not need as much fuel to get that dV.

[WizardlyMouse]

SOI changes definitely can happen, even when the object isn't affected by physics. I once had an eccentric orbit around Kerbin from one of my early failed Mun missions. I left it there, and poor Bill got ejected to interstellar space by the Mun. You can avoid it by changing your inclination to something less equatorial.

[AfailingHORSE]

Watch someone do this and have their station just flat-out disappear because it somehow got within the despawn-unfocused-objects threshold of a planet (20km on Kerbin, I don't know if it varies).

is there a mod that gets rid of that?

[Mephane]

Now I would really love to construct and launch a Duna Cycler, but I have absolutely no idea how to calculate the required orbit (i.e. apoapsis, I assume periapsis is where you start, i.e. Kerbin).

[MR4Y]

While thinking about interesting locations to place space stations, and the idea of putting a station in a highly eccentric orbit around Kerbol, with an apoapsis just outside of Eeloo's orbit and a periapsis closer to Kerbol than Moho, seemed intriguing. What I'm wondering is, would such a station be viable, or would unplanned encounters with other planets, and the gravity assists/brakes that the encounters caused, occur often enough to skew the station's orbit?

That would only be possible if the game had lagrange points and n-body physics.

[Merinsan]

That would only be possible if the game had lagrange points and n-body physics.

It's completely possible now.

Basically you're just setting up an eccentric Kerbol orbit.

The only problem is SOI changes that might occur. These do happen and can be disastrous. I once had a refueling ship in Duna orbit, waiting to be docked while I managed another arriving vessel. By the time I got back to it, it had encountered Ike and was in a Kerbol orbit. To properly eliminate this problem, you'd need to set up an orbit that is on a different plane. You could potentially time your orbit so there is a resonance with the other bodies, but you'd need to be exact or eventually they'd meet.