SCIENCE GOALS AND OBJECTIVES: UNMAGNETIZED PLANETS LIKE VENUS ARE ESPECIALLY SUSCEPTIBLE TO ATMOSPHERIC SCAVENGING BECAUSE THE SOLAR WIND INTERACTS DIRECTLY WITH THE UPPER ATMOSPHERE DUE TO THE LACK OF AN INTRINSIC DIPOLE MAGNETIC FIELD. RECENT VENUS EXPRESS (VEX) OBSERVATIONS CONFIRMED THE COMPLEXITY OF THE INDUCED VENUSIAN MAGNETOSPHERE ESPECIALLY GIVEN THE OBSERVED MAGNETIC RECONNECTION IN THE NEAR VENUSIAN MAGNETOTAIL. ON THE OTHER HAND PENETRATION OF THE INTERPLANETARY MAGNETIC FIELD (IMF) INTO AN INSULATING CRUST IS ROUTINELY SEEN AT THE MOON BUT THE IONOSPHERE OF VENUS PRESENTS AN INDUCED FIELD BARRIER WHOSE ABILITY TO SHIELD THE BODY VARIES WITH EXTERNAL PLASMA AND FIELD CONDITIONS. WE EXPECT VENUS TO BE INFLUENCED BY PENETRATING IMF IN CERTAIN CIRCUMSTANCES AND PLAN TO EXPLORE THE OBSERVATIONAL AND PHYSICAL CONSEQUENCES. THEREFORE IT IS CRUCIAL TO EXTEND THE PLASMA MODEL LOWER BOUNDARY TO THE PLANETARY INTERIOR. THE PRIMARY OBJECTIVE OF THE PROPOSED WORK IS TO STUDY SOLAR WIND INTERACTION WITH VENUS FOR THE FIRST TIME BY INCORPORATING THE PLANETARY INTERIOR IN A FULLY SELF-CONSISTENT MANNER. WE WILL MAINLY FOCUS ON THE INFLUENCE OF THE COUPLED PLANETARY INTERIOR (SUCH AS THE CONDUCTING CORE SIZE AND THE ELECTRICAL CONDUCTIVITY PROFILES) ON 1) THE ATMOSPHERIC ION LOSS OF VENUS AND 2) THE VENUSIAN MAGNETIC TOPOLOGIES UNDER A VARIETY OF SOLAR WIND CONDITIONS (INCLUDING EXTREME SPACE WEATHER EVENTS). WITH THE KNOWLEDGE FROM 2) COMBINED WITH VEX OBSERVATIONS THE PROPOSED WORK WILL ENABLE FURTHER CONSTRAINING AND HELP DETERMINE THE VENUSIAN INTERIOR STRUCTURES AND PROPERTIES. THIS NEW MODEL IS CAPABLE OF REVEALING HOW EXTERNAL IMF PROPAGATES FROM INTERPLANETARY SPACE TO SATELLITE ALTITUDES AND ALL THE WAY DOWN TO THE SURFACE AND PLANETARY INTERIOR IN A SELF-CONSISTENT WAY AND THUS ALLOW US TO INVESTIGATE THE TRANSITION TO MORE MOON-LIKE PLASMA INTERACTIONS. METHODOLOGY: WE WILL USE THE BATS-R-US MULTI-SPECIES MAGNETOHYDRODYNAMIC (MS-MHD) MODEL THAT HAS BEEN EXTENSIVELY VALIDATED AND APPLIED TO DIFFERENT SOLAR SYSTEM OBJECTS. WE WILL FIRST DEVELOP AND VALIDATE A CONDUCTING-CORE-SURFACE-TO-INTERPLANETARY-SPACE MS-MHD (CCSIS-MS-MHD) MODEL BY EXTENDING THE MODEL LOWER BOUNDARY INTO THE PLANETARY INTERIOR (THAT IS RIGHT UP TO THE SURFACE OF THE CONDUCTING CORE). THEREAFTER WE WILL STUDY SOLAR WIND INTERACTIONS WITH VENUS UNDER BOTH STEADY SOLAR WIND AND EXTREME SPACE WEATHER CONDITIONS. WE WILL CHOOSE ONE CASE OF PARTICULAR INTEREST (BASED ON VEX OBSERVATIONS) AND TRY TO LINK THE PLANETARY INTERIOR PROPERTIES (SUCH AS THE CONDUCTING CORE SIZE AND ELECTRICAL CONDUCTIVITY PROFILES) TO EXTERNAL MAGNETIC FIELD OBSERVATIONS BY VEX. THIS WILL ENABLE US TO STUDY THE EFFECTS OF THE INNER LAYER (WITH HIGH CONDUCTIVITY CORRESPONDING TO THE CONDUCTING CORE) AND THE OUTER LAYER (WITH LOW CONDUCTIVITY REPRESENTING THE MANTLE AND CRUST) ON BOTH THE ION LOSSES AND THE PLANET'S MAGNETIC TOPOLOGY (INCLUDING THE NEAR-PLANET MAGNETOTAIL RECONNECTION). WE WILL EVENTUALLY PUT FURTHER CONSTRAINTS AND HELP DETERMINE THE VENUSIAN INTERIOR STRUCTURES AND PROPERTIES. RELEVANCE: THE PROPOSAL IS HIGHLY RELEVANT TO THE ROSE SOLAR SYSTEM WORKINGS (SSW) PROGRAM SINCE THE PRIMARY GOAL OF THIS INNOVATIVE SCIENTIFIC RESEARCH PROJECT RANGES FROM THE INTERIORS OF PLANETARY BODIES AND PLANETARY ATMOSPHERES TO THEIR MAGNETOSPHERES. ALL OF THESE ELEMENTS WHICH ARE ENCAPSULATED BY OUR WORK CONSTITUTE THE CENTRAL TARGETS AND PRIMARY OBJECTIVES OF THE SSW PROGRAM. THIS PROPOSED WORK WOULD LINK TWO SEEMINGLY INDEPENDENT RESEARCH FIELDS 'PLANETARY INTERIORS' AND 'PLANETARY MAGNETOSPHERES' AND IS THUS CAPABLE OF POTENTIALLY REVOLUTIONIZING OUR UNDERSTANDING OF THE PROCESSES INVOLVED IN THE INTERACTION OF SOLAR WIND WITH UNMAGNETIZED PLANETS.