How do you change planes for planetary transfer burn in LKO?

[shoveycat]

The name sums it up, i cant figure out how to change planes for my transfer burns for Dres, Jool, etc, since there's no a/decending node markers when you aren't orbiting the same body The only way i know how is to escape Kerbin and do it there, however that's extremely inefficient. If you would, please tell me how you do it below.

[Newnard]

I escape Kerbin and do it there.

If you think about it, no matter what inclination you are at in Kerbin orbit, you are still at approximately the same inclination as Kerbin in solar orbit. Changing your Kerbin inclination doesn't really change your overall inclination in the solar system. So I think escaping Kerbin first isn't as inefficient as you think.

[shoveycat]

Well, if you arent in LKO, you arent taking advantage of the Oberth effect, trust me, i know it can be done, i just dont know how.

[Mokmo]

If you want to see your AN/DN around Kerbin, target Mun.

[shoveycat]

Never thought of that, thanks

[KerbMav]

When leaving a planets orbit you still have the planets velocity - you simply burn to add to this velocity - the overall vector will still be that of the planet your are leaving and therefore your inclination relative to the star will be almost the same too.

[Oddible]

You do realize that you can't line up your inclination with another planet while in orbit around Kerbin right? Even if you get your inclination identical you'd be on a different plane. Both Kerbin and your target, say Duna, are on planes relative to the sun, Kerbol. Until you get out of Kerbin's SOI you can't align your inclination to the sun.

[shoveycat]

Oh, okay. when do you do your plane changing burns then?

[possum]

After leaving Kebin's SOI at the ascending or descending node.

[Kasuha]

You can see AN/DN on the conic patch of your interplanetary trajectory. Then you can play with the maneuver until you get either AN or DN to the place where you intercept the planet.

Here I prepared you an example using very unoptimized trajectory way out of good start window.

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[DMagic]

It is definitely possible to match your target planet's inclination by changing your inclination in LKO. It's more complex than just looking at the planet's inclination though.

If you wait until Kerbin and the target planet are at a node then you can do the transfer burn at a high inclination to match, or nearly match the planet's.

I've done this many times for Moho, but it requires careful timing and tweaking of your inclination to get right. It's also not very feasible if you are already in orbit; you have to set this up properly at launch time.

[The_Rocketeer]

You do realize that you can't line up your inclination with another planet while in orbit around Kerbin right? Even if you get your inclination identical you'd be on a different plane. Both Kerbin and your target, say Duna, are on planes relative to the sun, Kerbol. Until you get out of Kerbin's SOI you can't align your inclination to the sun.

In theory this is possible, but only by timing your burn to coincide with the ascending/descending nodes of Kerbin to Jool (or whatever other planet) - i.e. when your Jool intercept point is directly on Kerbin's equator. Otherwise you will always have to make an inclination correction. That said, waiting for Jool and Kerbin to perfectly align for a single ascent burn at a realistic delta-v requirement isn't exactly what you'd call convenient.

I have always used the technique Kasuha described to reach other planets.

Edited October 20, 2013 by The_Rocketeer

[shoveycat]

Thanks for all the help, guys,It just seems that Kashua's technique is pretty Delta-V inefficient...

Edited October 20, 2013 by shoveycat

[The_Rocketeer]

It's worth considering that craft like the Voyager probes and Cassini/Huygens actually used a whole series of gravity fly-bys to build up their velocity high enough to reach the outer solar system. If you're looking for a really efficient way to get out to Jool and Eeloo, you'll want to figure THAT out.