You'll have to wait several updates. There's too much to do and the game doesn't actually support missions outside the starting system by default.
In order to have a mission outside the starting system, the system itself needs to be custom-made to hold specific custom planets with custom spawn settings.

Currently the vanilla story line exists in only two systems: The UCH Hideout System and the Starter System.
In order to do a proper story that crosses the galaxy, new systems and a new custom galaxy needs to be made and i'm too busy as it is.
1.8 might see a custom galaxy, with story systems and new planet-types.

Ah, okay, thanks.