Galacticraft
Boldly go where no Steve has been before with Galacticraft, an expansive mod that let’s you travel to, explore, and even colonise an entire solar system. Aside from all the interplanetary sightseeing, the main draw of this mod is the sheer amount of effort you'll have to put into it in order to escape Earth and its famously surly bonds. It’s a compelling and brilliantly constructed series of missions that rewards you with gameplay opportunities, like building a moonbase, pimping out your spaceship, and fighting evolved mobs on Mars.