Hard Science Futurism: What types of theoretical prefabricated materials would the first stellar generation ship carry to construct an O'Neil cylinder upon arrival?
Assuming we are talking about an era when Sol has a thriving space industry and the Solar system is broadly colonized. Current materials science supports structures up to 8 kilometers in diameter, and if large scale graphene production is possible, up to 100km in diameter, at least according to Isaac Arthor....