Mars Modules Edit
Build these 4 kits in the ShipYard on the Moon and shoot them off on Gamma 4 rockets or a Vasimr Rocket.
Once you have the Mars Parts Store and the Mars 3D Printer, you can start to build 2x2 structures on Mars. You can recycle any 1x1 buildings and they just return to your inventory to be landed again as 1 1x1 module or combined into a 2x2 module.
Build this Life Support Module first as this can be placed anywhere, and all other modules must attach to a 2x2 already in place.