title: Critical need for a swingby return option for early manned Mars missions.
authors.affiliation: University of Tennessee, Knoxville 37996, USA.
authors.forename: J E
authors.initials: JE
authors.lastname: Lyne
authors.forename: L W
authors.initials: LW
authors.lastname: Townsend
mesh_terms: D018480:Astronauts; D003359:Cosmic Radiation; D006801:Humans; D018535:Mars; D016272:Occupational Health; D011835:Radiation Protection / Q000295:instrumentation / Q000592:standards*; D019445:Solar Activity; D013026:Space Flight / Q000295:instrumentation / Q000592:standards* / Q000639:trends; D018531:Spacecraft / Q000295:instrumentation* / Q000592:standards; D014481:United States; D018557:United States National Aeronautics and Space Administration