An O’Neill Cylinder is a hypothetical space habitat designed for human habitation and long-term sustainability. It was proposed by physicist Gerard K. O’Neill in his 1976 book “The High Frontier: Human Colonies in Space.” The design concept incorporates two counter-rotating cylinders, each several kilometers in length and up to a few kilometers in diameter. These cylinders would rotate to generate artificial gravity through centripetal force. The interior of the cylinders would be designed to support human life by incorporating agricultural areas, residential zones, and other essential amenities.