How to eyeball interplanetary transfer?

[mellojoe]

So, Putting things in orbit is easy. I've sort of figured out how to get to the Mun and Minmus and back. Eyeballing these are fairly straight-forward. And the manuever nodes make it pretty easy.

However, I am failing all over the place trying to get interplanetary orbits. RIght now I'm having to use MechJeb to plot a manuever node for me. But I hate that idea. And I know there are other add-ons that will do it for you, but is there not a simple eyeball test for the planets?

[Domfluff]

You'll have to do the maths, or use an online calculator. This will get your phase angles for you to judge (this will, I'm sure, have an official solution at some point - the node system is great, but it falls down a little here).

Mostly I use Kerbal Engineer to get my injection/phase angles correct - that way only the calculations are being done for me, which I'm perfectly capable of doing, but sometimes it's not worth the effort.

[Guest]

There's also this web tool: http://ksp.olex.biz/

[Oggula]

I've used www.ksp.olex.biz since v0.17 to get phase angles. The rest can be done by hand, and it should cost less delta-v than mechjeb if you do it properly. Manouver node editor is useful for fine tuning though.

[Jod]

I've eyeballed Eve and Duna if you could call it that. I just eject myself to prograde/perigrade, set my periapsis/apoapsis to touch the planets orbit and wait for the planet/myself to catch up as if it is a rendezvous. Takes a while, but eventually when I am close enough I set a maneuver node and correct my speed slightly at the point where my orbit touches the planets so that in the next rotation i would get capture.

I mean, it's kerbals. They can wait a couple of years in space.

[mellojoe]

I've eyeballed Eve and Duna if you could call it that. I just eject myself to prograde/perigrade, set my periapsis/apoapsis to touch the planets orbit and wait for the planet/myself to catch up as if it is a rendezvous. Takes a while, but eventually when I am close enough I set a maneuver node and correct my speed slightly at the point where my orbit touches the planets so that in the next rotation i would get capture.

I mean, it's kerbals. They can wait a couple of years in space.

Wait ... do you mean you end up in a huge elliptical orbit around Kerbin where the Apoapsis hits the orbit of the planet, and then just wait a bunch of orbits for them to get close?

[ThreeMartiniLaunch]

Lately, I've started using http://alexmoon.github.io/ksp/ or http://www.eiden.fi/ksp/ to get phase angles.

I have little pieces of paper folded to 90, 45, 30, and 15 degrees. I go to the map view and zoom out where I can see Kerbin and my target, then hold the appropriate piece of paper up to the screen and time warp until the target is in the general area of the required phase angle.

Then launch and pray.

Haven't missed an encounter yet.

[Mr Shifty]

You don't need to eyeball it. Maneuvering nodes are your friends:

http://forum.kerbalspaceprogram.com/showthread.php/33547-Tutorial-Non-Hohmann-Interplanetary-Transfers

[Jod]

Wait ... do you mean you end up in a huge elliptical orbit around Kerbin where the Apoapsis hits the orbit of the planet, and then just wait a bunch of orbits for them to get close?

Yes. And then correct the speed slightly to get capture. Usually 50-100 delta v is enough if you do it 1 orbit in advance, the maneuver node is handy at that point.

*Not Kerbin. Kerbol. The Sun.

Though I've never went to Jool in this way. Mostly Eve. And 1 trip to Duna where I crashed into some mountains during reentry.

Edited June 13, 2013 by Jod

[tntristan12]

I use the protractor mod. Blessed useful tool, that...