Of Mice and Men: Rodent habitats in space have become essential to understanding human diseases on Earth

Long-duration spaceflight has deleterious effects on organisms adapted to life in Earth's gravity. For humans, some of these effects are relatively minor, rapidly resolved, and well understood. For example, going from Earth gravity to weightlessness can cause disorientation and nausea (space sickness), whereas returning to Earth after getting used to microgravity can cause orthostatic intolerance (various symptoms that manifest when standing but abate when sitting back down). Other effects of living in space are more persistent and potentially debilitating. Stemming from many organ systems responding to reduced gravity, these effects include cardiovascular and musculoskeletal alterations, neurovestibular and sensorimotor adaptation, immune dysfunction, delayed wound healing in soft tissues, and incomplete fracture repair in bones.