“Facts”? To take the Kerbal example, you could go read in a textbook that: “The Hohmann manouver is the most energy-efficient two-impulse maneuver for transfe

“Facts”? To take the Kerbal example, you could go read in a textbook that: “The Hohmann manouver is the most energy-efficient two-impulse maneuver for transferring between two coplanar circular orbits sharing a common focus. The Hohmann transfer is an elliptical orbit tangent to both circles on its apse line... The periapsis and apoapsis of the transfer ellipse are the radii of the inner and outer circles, respectively.” You could even memorise that fact and regurgitate it on the exam. But, speaking as someone with a physics degree, there was nothing like playing Kerbal to get a really intuitive feel for orbital mechanics. To go from “oh yeah, I vaguely remember something called a Hohmann transfer and I guess I could do some maths to work out the specifics if you give me some time” to “well, obviously….”