title: Medical challenges in space.
mesh_terms: D001826:Body Fluids / Q000502:physiology; D005260:Female; D006801:Humans; D008297:Male; D009041:Motion Sickness / Q000517:prevention & control; D010024:Osteoporosis / Q000209:etiology; D013026:Space Flight; D014893:Weightlessness / Q000009:adverse effects