I like the numbers

[danielw]

Hi everyone!

I've been playing KSP for a few weeks.  I suck at math, but got really interested in the numbers behind gravity and orbit. (Kerbal Engineer is such a helpful tool.)

Right now, my nemesis is the launch profile. Can I calculate the best gravity turn on a calculator?

If you play with spreadsheets, we should be friends.

[NathanKell]

Welcome to the forums and to KSP!

 

Since the optimal ascent path is a function of your launch vehicle design, your payload, and your desired orbit, it is not something that can be simply calculated. Even holding those fixed the optimal launch trajectory is a hard problem (people write PhD dissertations on that sort of thing). Further, the most optimal ascent may not be possible for you (it may exceed aerodynamic or thermal limits).

In general you want to minimize gravity losses while also holding down drag losses and steering losses. That involves getting as much horizontal velocity as you can as quickly as possible (in effect gravity losses are a function of how much you don't burn level with the horizon) while also making sure you get out of the atmosphere acceptably. Don't be tempted to over-enigne your launch vehicles, however--you may get to orbit with less delta V expended but you'll have paid more per tonne of payload in funds and mass.

[SorryDave]

Welcome to the forums!

Accent profile is best determined by trial and error, along with the sometimes conflicting advice from experienced players.

Each rocket has a different optimum profile based mostly from TWR and drag. I recommend building a rocket and trying different accent profiles. Measure success by seeing how much fuel you have left after getting into orbit.

Ang again Welcome!

[Guest]

This may be a useful baseline to work from.