Return from Bop

[technion]

Hey guys,

Having just completed a Joolean tour I'm looking to return home to Kerbin.

I'm currently in a Bop orbit - and it's a perfectly polar orbit, due I guess to a badly managed intercept. I didn't appreciate how lucky I was with every previous intercept having a near 0 heading. Now, unlike the perfectly planned transfers between moons, planning ejection isn't so obvious.

1. I'm imagining the most efficient thing is to first escape to Jool such that the pe gets nice and low, for maximum oberth effect. However, I can't see to plot an escape from this angle that actually reduces it. That means just escaping, followed by a less efficient burn to drop it.

2. Attempts to flatten the orbit around Bop seem incredibly expensive. Where is the best place to do it?

[Mr.Rocket]

I don't know number 1, but i know number 2. When you have a far out orbit, it is easier to change the orbit. In other words, extend you apoasis and periapsis first. Then since you are in a polar orbit, you will pass the equator at some point. That's the best place to level your orbit. Use a maneuver node! Bob doesn't have too much gravity anyways so it should take up to much delta-v.

[Kasuha]

Bop has negligible gravity. Burn anywhere to escape its SOI and you'll find yourself in Jool orbit quite close to Bop's. Then just burn for escape from this orbit, don't bother with lowering your Pe to Jool unless you're really short on fuel.

[technion]

Bop has negligible gravity. Burn anywhere to escape its SOI and you'll find yourself in Jool orbit quite close to Bop's. Then just burn for escape from this orbit, don't bother with lowering your Pe to Jool unless you're really short on fuel.

Thanks for that. I'm quite low on fuel so I'll got for that option.

So you would suggest the best place to deal with alignment after escaping jool?

[TheDarkStar]

Thanks for that. I'm quite low on fuel so I'll got for that option.

So you would suggest the best place to deal with alignment after escaping jool?

You want to be at the place where your orbital planes intersect that is higher than the other to use less fuel. Alternatively, you can just barely burn to leave Jool's SoI, warp to one of the places your orbital plane intersects with Kerbin's, and do your deceleration burn there. Your periapsis will be very close to Kerbin's orbit after that, even if you have the wrong inclination, and you can easily adjust your orbit to hit Kerbin. Since you aerobrake at Kerbin, it doesn't matter that much if you wait to change inclination until then, so this is probably a more fuel-efficient method.

[Kasuha]

Make sure you're escaping Jool already on Kerbin intercept trajectory. The best place to align it is your Jool low pass. Of course when you'll be going for that low pass you'll be near apoapsis on quite eccentric orbit so you can use that to prepare for inclination you'll need for the escape.