how to plan a gravity assist

Why don’t you use a planed burn? It’s good 👍

i tend to use all the fuel i have ._.

@SamTheFox thanks for the help, I'll try it in the game. If it's not difficult for you, when should you fly with Droo to meet other planets?

rendezvous with a planet

make your trajectory as close to the planet as possible (but not in the atmosphere)

make sure your escape trajectory is pointed towards prograde relative to the planet's orbit around the sun (unless you want to go further into the sun)

keep doing this until you either run out of fuel or get to your destination

if you're asking to set up the planned trajectory towards a distant planet, place a maneuver node on pieces of the trajectory where you enter the planet. that way you can use the planet's gravity assist to basically get a free boost of speed, with the help of a thruster of course