Aerobraking math?

[noahtech]

Does anyone know how to do the Math for aero-braking? I've done it in KSP by just using trial and error, but how do they predict how much they'll slow down in real life?

[K^2]

Yeah. You need to numerically integrate the trajectory. There isn't a formula for it. A very simple script can be written for it, though. If you want to be able to do this yourself, I would recommend learning how to use Octave.

[Norpo]

Alternatively, you can use this handy web-based aerobraking calculator: https://alterbaron.github.io/ksp_aerocalc/

(EDIT: It will probably be obsolete in the next update though; aerodynamics are getting overhauled entirely)

[Firov]

You might take a look at the following links. The equation described is meant as a "simple" equation for determining the velocity lost, and resulting orbital contraction, during aerobraking.

https://solarsystem.nasa.gov/docs/5_Forget_Aerobraking_Equation.pdf

http://solarsystem.nasa.gov/docs/5_a167.pdf

Note that even though these are meant to be "simple", that's simple in relative terms when compared to other means of calculating the effectiveness of aerobraking.

[K^2]

That's brilliant. I was thinking that there might be a way to do an estimate based on similar assumption, but it felt like a lot of work. Glad to see that someone has already done the work.