Figuring out nodes while in Kerbin orbit

[Klapaucius]

If I want to fly to Eeloo (or anywhere that is far off the orbital plane from Kerbin), it seems it would be most efficient to adjust my orbital plane while in Kerbin orbit rather than in orbit around Kerbol after having escaped Kerbin.

If I set Eeloo as my target, I don't get the ascending and descending node indicators until I have escaped Kerbin and am in orbit around Kerbol. Is there a trick to figuring this out?  Am I correct in my assumption that it would be more efficient, or does it not matter?  It does seem, however that you can really mess up your orbital window if you try to do these maneuvers while in Kerbol orbit.  Is there something, perhaps in Kerbal Engineer, that would tell me that I missed?

Edited March 15, 2020 by Klapaucius

[VoidSquid]

Hey @Klapaucius,

This reminds me of the discussions how to get to Moho, with its inclined orbit, this discussion here

 

It's not that different, imo. Basically (and yes, it does cost you some dv) you try to make a Hohmann transfer being in the Sun's SOI in a way that you start your burn from Eeloo's AN or DN, and end at Eeloo's AN or DN, minimizing the dv needed for any plane change, ignoring the transfer windows.

Sounds a bit cryptic maybe, but that's how it worked for me.

[Starhawk]

9 hours ago, Klapaucius said:

Is there a trick to figuring this out?

The trick is that you cannot match the inclination of a target body by doing a Hohmann transfer burn.

This is because the place you burn to match your target's plane must be at the AN or DN.

But if you are doing a Hohmann transfer burn from Kerbin when Kerbin is already at either the AN or DN, as VoidSquid alludes to above, you do not need to make an inclination change.  You encounter your target at the next AN/DN.

On the other hand, if you are doing a Hohmann transfer and you are not at the AN or DN when you need to leave to hit the transfer window, then you will need to wait until you get to the DN or AN to make your plane change (i.e. out in interplanetary space).

Happy landings!

[bewing]

As far as I'm concerned, this is exactly why god put other planets in the solar system. They exist to do your plane change maneuvers for you. You may not think slingshots give you enough of a dV boost to do you much good, but they can pretty much eliminate the need for plane changes, and those are very dV-expensive things.

[RoninFrog]

More efficient than changing planes while in Kerbin orbit is to change planes while launching to Kerbin orbit instead of just gravity turning directly east.  It is a lot more difficult, though.

Edited March 15, 2020 by RoninFrog
typo

[Starhawk]

1 hour ago, RoninFrog said:

More efficient than changing planes while in Kerbin orbit is to change planes while launching to Kerbin orbit instead of just gravity turning directly east.  It is a lot more difficult, though.

I believe you misunderstand.

The Original Poster is talking about the inclination of the orbit around the sun on the way to another planet, rather than the inclination of the craft's original orbit around Kerbin.

Happy landings!

[Klapaucius]

3 minutes ago, Starhawk said:

I believe you misunderstand.

The Original Poster is talking about the inclination of the orbit around the sun on the way to another planet, rather than the inclination of the craft's original orbit around Kerbin.

Happy landings!

Yes, but my question was about whether it makes more sense to change that inclination with in Kerbin Orbit or while orbiting Kerbol. The general consensus seems to be to do neither, however.

[RoninFrog]

10 minutes ago, Klapaucius said:

Yes, but my question was about whether it makes more sense to change that inclination with in Kerbin Orbit or while orbiting Kerbol. The general consensus seems to be to do neither, however.

Least dV to most dV:

1. Eeloo intercept at An or Dn (no plane change required)

2. While launching to Kerbin orbit (less boost from Kerbin's rotation/orbit)

3. While in Kerbin orbit (have to alter orbital velocity)

4. While burning for Eeloo (have to alter escape velocity)

5. While orbiting Kerbol (have to alter Kerbolar velocity)

[Klapaucius]

3 minutes ago, RoninFrog said:

Least dV to most dV:

1. Eeloo intercept at An or Dn (no plane change required)

2. While launching to Kerbin orbit (less boost from Kerbin's rotation/orbit)

3. While in Kerbin orbit (have to alter orbital velocity)

4. While burning for Eeloo (have to alter escape velocity)

5. While orbiting Kerbol (have to alter Kerbolar velocity)

Thank you. Very helpful list. I've spent a lot of time with planes, but only now really going back to rocketry. I have a lot to learn.

Edited March 15, 2020 by Klapaucius