I'm pretty sure the devs can think of something if they ever plan to implement this, I haven't read the whole thread, not sure if it contains any amazing ideas that make this irrelevant. It would also be great if the OP could include some of the best ideas in the first page. However, here's what I got, sorry if it's been repeated, can't be arsed to read it all. Upon leaving the SOI of the sun, some set radius away from the sun, an interface comes up (Assuming you have some fancy engine part that is required, if not, you're left to the kracken. How you get that device in career mode is up to the devs, I like monolith involvement). Maybe in career mode, the player has to find the right ascension and declination of the star through some other means, and enter that information before their engine will work. Perhaps in the future the interface could be a fancy galaxy map or something. For now we assume it's a list with the names of each system in it. You select a system from this list, and then see your engine do some fancy effects. It would be amazing if they could make a fake type warp drive, engine turns all blue, makes cool noises, and then the ship moves away really really fast until it teleports. SEE: Star trek: TNG. Maybe just move the camera backwards instead of the ship, I don't really know. However, this really isn't necessary at all, it just gives the nerd in me a hardon. But after that, simply have the reverse effect happen, in the new system. And then you're traveling at the same speed you left the kerbol system at, but this time, towards the center of the new solar system. Like people have said, first and foremost it is a game, meant to be fun. There's no realistic way to get to another solar system in KSP and have it be fun. Rules will have to be broken, and things will have to be made up for this to work. I think it's best if the amount of sci-fi usage is minimal though. TL;DR: Go to edge of kerbol system, a menu comes up if criteria is met (fancy engine effect maybe), and you're in new system at the edge, same speed as when you left.