Looking at the information accessible to me it appears space colonies should happen before mars colonization due to valid arguments about our bodies handling low g for a long time .Wondering how good iron nickel is for making the shell of a rotating cylindrical space colony be handy to have a use for massive amounts of waste products from asteroid mining .I like the idea of small people 50kg average say playing basketball doing massive slam dunks under pseudo gravity hopefully mars equivalent but whatever works .Synergy is going to be critical in paying the bills for this anybody think of any other low g sports to televise to produce revenue ?