title: Commercial human spaceflight: the new challenge for aerospace medicine.
authors.forename: Jonathan B
authors.initials: JB
authors.lastname: Clark
mesh_terms: D000337:Aerospace Medicine / Q000639:trends*; D003132:Commerce / Q000639:trends*; D006801:Humans; D013026:Space Flight / Q000191:economics* / Q000639:trends; D018531:Spacecraft; D014195:Travel; D014481:United States; D014893:Weightlessness