Explaining how: What I meant was that some SFS noobs think it is impossible to go to Mars cuz they think the rocket will stop if the engines were off, but actually not. You see, SFS let's you see the trajectory where the rocket is flying. If you wanna go to Mars, Launch your rocket into Earth orbit, Navigate to Mars, And the game will show you the best timing to go to the planet. Then, Wait for Earth to orbit long enough so the planet transfer window will line up, But if you don't time warp, It might take you several months before they line up, so just click on the transfer window and click "Timewarp Here"
After those had lined up, Place ur rocket on the designated transfer window for the rocket. And line your rocket up with the dashed lines, This is the most important thing. You gotta accelerate 700 m/s so the trajectory of the rocket gets an encounter on Mars. Just like lining up Earth to the planetary transfer window, It might take you several months to reach Mars. Again you can Timewarp there, and I recommend to Timewarp near the encounter or on the periapsis (which is the closest point the orbit is to the planet,) And burn your engines so that you slow down and get an orbit.
I hope this was helpful! Have a good gameplay!