EDIT: Yes I know that thing was the ball on top of the colony ship but my question is what were they seeking to do with it? Simple question with multiple possible answers... i think. We all know by know that giant servitor that serves as the raid entrance in Foundry 113 that separates the plaguelands from the original cosmodrome. But what were the fallen seeking to use that servitor for? Well to understand this we need to know their backstory. As we all know, the fallen refer to the Traveler as the great machine which gave them life, and they're still trying to reclaim it. That is, until they found SIVA. My theory is that the fallen sought to use that servitor as a second Traveler, one that would obey the fallen and provide them with ether and god hood. They might have even used it to lay siege to the city! Quite devious if you think further on it :/