In the 1980s and 90s, the was an organization known as the space island group. they intended to build and operate there own fleet of space shuttles, and to bring the fuel tanks to orbit. how credible is the idea of a fuel tank station, or using tanks for on-orbit infrastructure? What if we could bring SLS fuel tanks to orbit? how economical would this be compared to inflatables? How would we design a rocket if we wanted to bring the tanks to orbit?