Trying to intercept back to Kerbin with a tiny amount of fuel left; I've luckily managed to get into a flat orbit that intersects with the Kerbin orbit, so I know all I'd need to do really is to wait. But I know I could be waiting a theoretically very very long time to have a random intercept.
I know it must exist out there, I'm just not sure of the exact wording or name of it, where a tiny amount of deltaV might change that natural intercept from dozens of years to only a few.
Visually, it feels like I'm trying to align two sin waves to match up at a specific trough; is there a calculator or just plain math diagram I can setup? Knowing the orbital periods of the respective bodies, and being able to see the phase angle at the point of intercept, etc, I know it all combines somewhere to tell me how much to change the period to create an intercept if I can tolerate many years of waiting.
Edit: Managed to hack together an idea using sin waves and Desmos.com, just created two waves that showed their orbital periods in terms of days to return to a specific location, then added those waves together to see how they aligned and found a good trough to target.
