Rotating an elliptical orbit

[DrDress]

How do eaily rotate an elliptical orbit into an other. I know that I can make do it by making the orbit circular and then making it elliptical once again from a different position. But my gut tells me that there is a simpler way.

 

http://imgur.com/a/8nDDk

[Shadowmage]

34 minutes ago, DrDress said:

How do eaily rotate an elliptical orbit into an other. I know that I can make do it by making the orbit circular and then making it elliptical once again from a different position. But my gut tells me that there is a simpler way.

 

http://imgur.com/a/8nDDk

If, as in your image, your orbits intersect at any point you can do a single burn to change from one orbit to the other -- using a combination of in/out radial and pro/retrograde depending upon which intercept.  Place a manuever node at the intersect point and play around with the radial and pro/retrograde amounts.

If the orbits do not intersect than you will need to burns, one to create an intersect, and another at the intersect to change into the desired orbit.

So.. your gut is not far off aside from some special situations.

Now... which one is the most efficient fuel wise?  That is a bit beyond my expertise and math understanding of orbits, but experience tells me it is likely some strange bi-eliptic / multi-burn transfer, first burning to raise your orbit until an intercept, and then burning at the higher of the two intercepts to move to the desired orbit.

[Starhawk]

You can do it in a single burn down low but it will cost you.

It's much more efficient to do two burns.  First circularize at the apoapsis and then burn retrograde when you get to the desired location for the new apoapsis.  Much less dV required.

Happy landings!

 

 

Edited October 20, 2016 by Starhawk

[Rosco P. Coltrane]

I remember reading (and that's pretty much it) that past a certain degree of inclination change you'll loosing Dv to some... some effect which I can't remember.

So if we were to assume that I am remembering correctly , you might what to check that out, instead of a single big inclination change, you might want to do two smaller ones...

EDIT: Why I always find the thread I'm looking for 10 seconds after posting?

Here's the thread I was thinking of... probably

 

Edited October 20, 2016 by Rosco P. Coltrane

[DrDress]

Thanks for all the good replies!

[ForScience6686]

That's a big change there.  I guess if it were me I would raise the pe until the orbit is circular and match inclination at a high orbit, then match the orbit.  Not sure if it's the most efficient, but anytime I've needed big inclination changes, I try and do it while moving as slow as possible, usually at the ap.  But the transfer you're making is much larger and difficult to put the ap where you need to do the burn.  

Unless you have a high twr ship, I wouldn't try to change inclination at the current intersection.  You're moving quite fast during that point, which makes it a bit harder.