Every civilization starts with one explorer unit. Every explorer have 1 expedition module (more with development). There are plenty of remaining on the planet surface, either from human ships or alien in nature. When the site is explored it will disappear, use the module and give some nice reward, especially Artifacts(l). Modules are renewed when the unit visit a city. Now we found a Crashed Satellite! The question is, should we excavate the site or continue to search resource pods? Resource pods are like ruins in civ games, but they can also offer artifacts. And the first 50 turns are crucial, as every other player is searching for pods, and crash sites.