Download Alien Sky Free Unity. 

A pack of over 100 models +sounds +scripts +textures and more!

Package includes:
-Playable character with weapons
-Alien flora
-Planetary buildings
-Modular interiors
-Space station
-Spacemen
-2 types of androids
-5 types of spaceships
-Rideable hoverbike
-Drivable car
-Sounds
-Scripts
-sci fi Props
-Nebulas
-Terrains
-Meteors
-Much more!