Regenerative medicine is vital for counteracting astronaut bone loss in microgravity, where reduced mechanical loading accelerates osteopenia and impairs fracture healing. Current countermeasures like exercise and drugs help, but advanced regenerative solutions are needed. Bone-on-chip (BOC) technology, a microfluidic system mimicking bone physiology, enables precise studies of bone formation and degeneration in space. Adipose-derived stem cells (ASCs) committed to osteogenic differentiation (osASCs) offer a promising alternative to primary osteoblasts due to their ease of isolation, expansion potential, and strong regenerative properties. Integrating osASCs into BOC models facilitates research on bone loss mechanisms and novel osteoporosis treatments. This chapter details ASC isolation, osteogenic differentiation, and application in microgravity-simulating platforms, with the aim of contributing to progress in both space medicine and bone regeneration on Earth.