This is a collection of spaceship parts that you can use to to make any sort of space vehicle.
Layer one is your workspace,
Layer two has hull sections,
Layer three has smaller components,
Layer four has an engine builder you can use to make your own engine designs
Layer five has some greeble type things
Layer twenty has a couple of example ships
Have fun, and be sure to post your designs on the forum post accessed by clicking on "visit author's site"