“Exterior of Double Cylinder Settlement” by Rick Guidice (1975) Commissioned by NASA Ames Research Center, this painting visualizes a proposed space habitat known as the O’Neill Cylinder — a pair of 32 km-long rotating cylinders designed to simulate Earth-like gravity and support up to a million inhabitants. Created during a series of NASA/Stanford summer studies in the mid-1970s, Guidice’s work helped translate complex engineering into compelling visions of human life beyond Earth. This image is in the public domain and part of a larger body of speculative space art that continues to inspire architects, futurists, and dreamers alike. “This image lived quietly on the cover of a withdrawn library book for decades. Now it orbits here — a reminder that the future once imagined is still waiting to be built.”