This structure was designed to allow long stays in outer space, avoiding negative health impacts on astronauts. Introducing internal stresses in the metal, without human presence, allows the structure to expand freely and evolve into a toroid in ZERO gravity. When making it spin around its axis, gravity offers earth-like work conditions for occupants. This avoids short-term disorientation and proprioceptive system disruptions to long-term bone decalcification and muscle atrophy.