Prof Dava Newman 16. 423J/HST515J Space Biomedical Engineering and Life Support Solar electric propulsion mission concept HEO LEO Electric Propulsion(EP)space Crew delivered in“ small” Remainder of trans-Mars Space tug returns fo tug performs low-thrust transfer injection performed by refueling and next for Mars-bound cargo to High transfer vehicle.X-38 chemically-propelled system assignment( faster or more Earth Orbit(many months derived(few day efficient return since no rendezvous time payload present)Prof. Dava Newman 16.423J/HST515J Space Biomedical Engineering and Life Support 4 Solar Electric Propulsion Mission Concept (OHFWULF3URSXOVLRQ(3VSDFH WXJSHUIRUPVORZWKUXVWWUDQVIHU IRU0DUVERXQGFDUJRWR+LJK (DUWK2UELWPDQ\PRQWKV WUDQVIHU &UHZGHOLYHUHGLQ³VPDOO´ FKHPLFDOO\SURSHOOHG WUDQVIHUYHKLFOH; GHULYHGIHZGD\V UHQGH]YRXVWLPH +(2 5HPDLQGHURIWUDQV0DUV LQMHFWLRQSHUIRUPHGE\ FKHPLFDOO\SURSHOOHGV\VWHP 6SDFHWXJUHWXUQVIRU UHIXHOLQJDQGQH[W DVVLJQPHQWIDVWHURUPRUH HIILFLHQWUHWXUQVLQFHQR SD\ORDGSUHVHQW /(2