Create a stable orbit that changes SOI

[thereaverofdarkness]

The challenge is simple yet deceptively difficult (or I'm just not as brilliant as I like to think)--

Place any object/craft into any orbit anywhere, with the orbital path crossing out of the local Sphere of Influence (SOI) or into another SOI at some point along the orbit. It doesn't have to happen every orbit, it could happen less often, say, if you have this object orbiting Duna near Ike and only every tenth orbit of Duna does it cross into Ike's SOI.

Scoring is the number of cycles your object can make before its orbit destabilizes and it is ejected from the primary SOI, crashes, or enters into an orbit around a different body. A cycle is defined as either one orbit or one transition across a SOI boundary, whichever happens less often. If your object's orbit is greatly disturbed but remains in orbit around the same body and is still able to intersect the SOI it originally was, then it may still continue cycling (though it might not last many cycles after that).

The goal here is to create a truly stable orbit that transits SOI, but I don't think this is actually possible. So then the challenge lies upon you guys to see how stable you can get one of these.

Leaderboard:

1.) NERVAfan - 4

Edited December 14, 2014 by thereaverofdarkness

[Superfluous J]

I think a normal (90 degrees to the plane) orbit around Jool that just touches Pol or Bop's orbits would be the best, but I can't be arsed to set it up. You could probably get clever and make it as close to resonant (like 2:1 or 3:1 or whatever) as you can so in theory they could never ever touch.

[thereaverofdarkness]

My entry (composed of utter failure):

Setting up a high orbit right at the edge of Kerbin's SOI...

Finalizing the orbit...

Now it just barely extends outside of Kerbin's SOI.

Looks like we aren't coming back... =(

Edited August 18, 2014 by thereaverofdarkness

[thereaverofdarkness]

I think a normal (90 degrees to the plane) orbit around Jool that just touches Pol or Bop's orbits would be the best, but I can't be arsed to set it up. You could probably get clever and make it as close to resonant (like 2:1 or 3:1 or whatever) as you can so in theory they could never ever touch.

That's an interesting idea! Now if we just had someone clever (and bored) enough to set it up!

I see what I did wrong with mine. Since when it changes SOI it stops getting pulled by Kerbin entirely, it basically just slingshots it away. Having the orbit so close to the edge already was probably a bad idea, but more importantly the way I got this to work (accidentally) last time was probably due to Kerbin intercepting the craft. It probably left Kerbin's SOI on the leading edge and going slower than Kerbin.

[Red Iron Crown]

edit: how do I do spoiler tags?

Your opening tag must be [noparse]

[/noparse].

[cantab]

This is basically a challenge to set up a "cycler" trajectory - one that encounters one or more celestial bodies on a regular basis. It seems to boil down a repeating free-return trajectory, and is been something I've been meaning to look at for a while, so maybe I'll give it ago, though setting one up that requires no course corrections may be a tall order in KSP.

http://en.wikipedia.org/wiki/Lunar_cycler

http://en.wikipedia.org/wiki/Mars_cycler

[ihtoit]

Kerbin's SOI is about 80,000km.

So, a resonant Kerbolar orbit with its closest approach distance to Kerbin being just inside this should give you at least a semi-stable orbit. Resonant orbits don't have to be normal to the ecliptic, but it does help to avoid other spheres.

I'll see what I can set up later (maybe tomorrow).

[Jett_Quasar]

I'm thinking the best way to do it would be to just nick the outer edge of the SOI of a small moon like Gilly. A cycler trajectory would be cool but I don't think the game mechanics would support a stable orbit. Even on the real world minor course corrections are required.

JR

[Superfluous J]

I'm thinking the best way to do it would be to just nick the outer edge of the SOI of a small moon like Gilly. A cycler trajectory would be cool but I don't think the game mechanics would support a stable orbit. Even on the real world minor course corrections are required.

JR

I agree, but you could make it last a LONG time.

I figure 90 degree tilt, and put your periapsis right at Gilly's periapsis (inside it by Gilly's SOI radius minus, say, 1km) and your apoapsis at the edge of Eve's SOI. That way you and Gilly both spend the least amount of time in the area and unless you BOTH hit periapsis at EXACTLY the same time, you'll never interact. and when you do, you may even survive it and continue on.

I'd never actually do this in game though, it'd make burning to Moho on Ion engines seem like a quick run to the corner store for snacks.

[thereaverofdarkness]

unless you BOTH hit periapsis at EXACTLY the same time, you'll never interact.

But it only counts as a cycle if you do.

You have to cross that SOI boundary minimum once per cycle as per the challenge rules. If you set up a resonance that never actually gets you into any other SOI, you won't score any points. Just the same, it would be pretty neat though. If someone does something like that, I might have to come up with an alternate scoring system.

[Superfluous J]

Oh I misunderstood the rules. You want cycles of interaction, and I thought you wanted orbits of the parent body until ejection or crash.

Yeah without pure mathematical precision this would just be an exercise in trial-and-error for me.

[Im The One]

I'm trying this challenge, so far have gotten two cycles but i got work so i set in orbit around the mun for now. pics will come later

[Shenennigans]

I'm far and away from being a Scott Manley, but it seems if you entered into a retrograde orbit around Eve, with one end of the orbit matching up with the innermost section of Glily's SOI, and the other end of the orbit matching up with the outermost section of Gilly's SOI, the small but opposite course corrections you are getting would cancel and you could have an infinitely stable orbit that changes SOI twice per orbit (well 4 times, into and out of Gilly's SOI twice). Sounds like an existential hell setting it up though. Might give it a shot when I get home from work lol.

[NERVAfan]

I made a Kerbin orbit which intersects the Mun's SOI. It survived 4 Mun encounters; the 5th pitched it into solar orbit.

EDIT:

Here's the orbit I started with

Here's the last one that still intersected Mun's SOI:

I have a bunch of intermediate screenshots too, I'll post them if you want more.

Edited November 1, 2014 by NERVAfan