All you need is time. And money. And resources. Okay, so it's not that easy. But you can do it!
As a part of missions rewards, Explorers will earn ORE, which can then be refined into a variety of resources such as iron, gold, and various elements. Resources will vary in rarity and each structure, upgrade, and item will require a different combination of refined resources and CLNY to craft.
In early iterations, ORE will be introduced before resources have been developed. At that stage, ORE will be usable across the board for crafting and upgrades.