I would have posted this in a previous discussion, but my input dos not really fit with them b/c they are all about multiple stars in one save. My idea: Once you have maxed out your research in a save, a new option will be available when starting a new save. This will be the new star system. You would start in the VAB or SPH with a budget to build your inter-star rocket. When done the ship will be placed entering the system on a hyperbolic trajectory. Now, it goes without saying that, at this point in development, we would need resources, extra-planetary launches, (and perhaps a kerbal breeding system?). Otherwise, this idea is completely useless.