How to See Inclination Nodes After a Gravity Assist

[Andrew Hansen]

I'm doing the Kerbin Cup Whackjob challenge with team I Think We Broke It, and trying to get some efficient gravity assists to go to some weird planet that I can't exactly reveal right now. I'm trying to get a gravity assist around Eve, but right now I can't do it very well because I have a 2.0 degree inclination difference. My idea is thus to get two gravity assists around Eve - one to cancel out my inclination with Eve, and one to give me a boost out to the weird planet I'm going to.

My problem is that I can't see the inclination relative to Eve before I have my encounter, so I can only repeat tests over and over until I get something that works. This is very annoying. Is there a way to see my inclination (besides eye-balling it) in my resulting orbit after an Eve gravity assist?

Thanks for any answers,

Andrew

Edited July 9, 2014 by Andrew Hansen

[Taki117]

If you are staring at patched conics BEFORE the assist, no, but if you have already performed the assist you can select Kerbin as your target (Since it has a 0 degree inclination) and judge your inclination from there.

[Pecan]

"two gravity assists around Eve - one to cancel out my inclination with Eve,"

No gravity assist will change the inclination around the planet you're flying-by so the inclination after your first Eve fly-by will be exactly the same (2 degrees) as before.

[Yasmy]

Pecan, you are being unnecessarily pedantic.

Quite obviously he meant intersecting Eve from Kerbol orbit to change his Kerbol inclination, which I'm sure you knew.

[Kasuha]

I'm doing the Kerbin Cup Whackjob challenge with team I Think We Broke It, and trying to get some efficient gravity assists to go to some weird planet that I can't exactly reveal right now. I'm trying to get a gravity assist around Eve, but right now I can't do it very well because I have a 2.0 degree inclination difference. My idea is thus to get two gravity assists around Eve - one to cancel out my inclination with Eve, and one to give me a boost out to the weird planet I'm going to.

My problem is that I can't see the inclination relative to Eve before I have my encounter, so I can only repeat tests over and over until I get something that works. This is very annoying. Is there a way to see my inclination (besides eye-balling it) in my resulting orbit after an Eve gravity assist?

Thanks for any answers,

Andrew

When you're setting up the assist (using a maneuver), watch the trajectory after you leave Eve SOI. Put a maneuver (0 m/s dv) on that trajectory outside Eve SOI and you will see inclination markers if you have Eve selected as target.

Note that, though, you don't need to set up your trajectory to match Eve inclination. Select your secret planet as target instead, and make sure you make the other intersect with Eve orbit at one of inclination markers with your target instead. That will be way more useful.

"two gravity assists around Eve - one to cancel out my inclination with Eve,"

No gravity assist will change the inclination around the planet you're flying-by so the inclination after your first Eve fly-by will be exactly the same (2 degrees) as before.

That's obviously not true.

Edited July 6, 2014 by Kasuha

[Andrew Hansen]

When you're setting up the assist (using a maneuver), watch the trajectory after you leave Eve SOI. Put a maneuver (0 m/s dv) on that trajectory outside Eve SOI and you will see inclination markers if you have Eve selected as target.

Note that, though, you don't need to set up your trajectory to match Eve inclination. Select your secret planet as target instead, and make sure you make the other intersect with Eve orbit at one of inclination markers with your target instead. That will be way more useful.

Thanks Kasuha, I will be sure to try that. I have a lot to learn about gravity assists! I've learned that the Arkingthaad Super Lite (the giant vessel for the challenge, if you're not following) is a hard practice vessel though, so I decided to try an easier target.

I learned a lot about gravity assists from this video by allmhuram: