Aerobraking

[King Matthew]

I have never doen arobraking before in KSP, and I want to know if thier is any way to calculate how deep to get into the atmosphere, without falling to the planets surface.

[InfinityJason]

I'm still learning the art of aerobreaking, it depends on each planet and how dense their atmosphere is, its just a case of trail and error, just quick save and keep trying to come in at different altitudes.

[Nats]

Depends on your entry speed as well - I've aerobraked into a Kerbal orbit coming from the Mun and with a Peri at around 30k height and coming in pretty fast and it was quite a ride!

[ThatBum]

Aerobraking on Duna isn't worth it unless you're landing. The atmosphere is much too thin[wiki.kerbalspaceprogram.com] to aerobrake at any sensible altitude. If you orbit low enough for it to make a difference, you may smack into a mountain.

Aerobraking on Kerbin, Eve, and Jool is possible however. I agree with Jason here, it is a thing you need experience to master. You need to know how low to go to get your apoapsis where you want it, and indeed not to lose orbit entirely. Maybe send an expendable probe to Jool and get a feel for it, Galileo[en.wikipedia.org]-style?

[King Matthew]

Thanks for the input guys. Its mostly experience.

[Drown Babies]

You can use the landing guidance from mechjeb to predict the outcome of aerobraking, you still have to set the periapsis yourself to determine the ideal elevation, but it seems to work.

And you also have to take into account how big your spacecraft is and how much drag it has. My tiny Laythe orbiter had very little drag, so I had to go down to around 18000m (the atmosphere starts at about 50000m) above Laythe to get into a stable, but very elliptical, orbit. My big Laythe base had much more drag though, so I only had to go down to about 28000m, and that was just about enough to bring me in for a landing.

You can aerobrake around Duna, I did it with another good size base to stabilize my orbit. It is a bit trickier though since the atmosphere is so thin.

[tam1g10]

The easiest way to aerobrake is to approach a planet at full solar orbital speed because your speed will be quite consistant and therefore so will the periapse hight you need. To get into orbit aim for around 45,000 meters for Kirbin and 125,000 meters for Jool. Watch out for Eve that atmosphere is thicker than you think you propably won't need to go below 70,000