title: Preface.
authors.forename: F A
authors.initials: FA
authors.lastname: Cucinotta
authors.forename: H
authors.initials: H
authors.lastname: Nikjoo
mesh_terms: D000337:Aerospace Medicine; D003359:Cosmic Radiation; D006801:Humans; D008954:Models, Biological; D011830:Radiation Effects; D011835:Radiation Protection; D012307:Risk Factors; D013026:Space Flight; D014893:Weightlessness