The idea of re-purposing an (ideally) empty rocket fuel tank and turning it into a space habitat has been around for a long time, because it’s a really appealing idea. America’s first space station, Skylab
, was designed from a Saturn V rocket’s upper-stage fuel tank, albeit one that was never filled with fuel. Now NASA has selected a company to develop habitats made from used rocket fuel tanks.
Source: Gizmodo – NASA Wants To Make Space Habitats From Orbiting Rocket Fuel Tanks