---------Coordinates are x-201y36z-21----------You have to find legendary maps by opening chests. (And you need 80 goldbricks to unlock large worlds because all legendary bricks are in large worlds only.) When you find 4 of them build it to a giant QR code grab your landforming tool and make it flat some codes required different paintings or you need to remove something from the code to get it to work. Scan that QR code with your Smartphone until you get the coordinate's (or use the one above) go into your rocket and type in the coordinates on the right side of the screen. Fly to the new planet and go to the coordinates by using a heli or something like that. Here is a link to a video. Credit goes to the owner.
https://m.youtube.com/watch?v=P5vWyOZbAB8