THIS PROPOSAL WILL ADDRESS THE REDUCTION OF SPACE STRUCTURE MASS THROUGH THE DESIGN AND SCALABLE FABRICATION OF OCTET AND KAGOME BASED OPEN CELL LATTICE STRUCTURES AND THOSE BASED UPON RECENTLY DISCOVERED CUBIC + OCTET FOAMS WITH CLOSED (OR ALMOST CLOSED) CELLS. THE LATTER CAN REACH THE UPPER BOUND THEORETICAL STIFFNESS OF CELLULAR MATERIALS AND PROVIDE THERMAL ISOLATION AND VIBRATION DAMPING WHILE THE OPEN CELL LATTICES CAN BE DESIGNED TO APPROACH THE UPPER STRENGTH BOUND AND HAVE POTENTIAL FOR HEAT EXCHANGE AND IMPACT ENERGY DISSIPATION. MODELS WILL BE DEVELOPED THAT RELATE LATTICE TOPOLOGY AND RELATIVE DENSITY AND THE SOLID MATERIAL SYSTEM FROM WHICH THEY ARE MADE TO THE LATTICE ELASTIC MODULI AND ITS STRENGTH TENSOR COMPONENTS. THESE ANALYTIC AND COMPUTATIONAL MODELS WILL BE EXTENDED TO ADDRESS CELL SIZE AND DIRECTION-DEPENDENT FRACTURE RESISTANCE AS WELL AS IMPULSE (DYNAMIC) LOAD MITIGATION HYPER-VELOCITY IMPACT AND THERMAL MANAGEMENT PERFORMANCE. CONCEPTS FOR THE MECHANICAL (SNAP-FIT) ASSEMBLY OF LARGE SPACE STRUCTURES FROM LATTICE COMPONENTS (TRUSSES AND WEBS) MADE BY A VARIETY OF SCALABLE PROCESSES INCLUDING METALS ADDITIVE MANUFACTURING SPARK PLASMA AND/OR PRESSURE ASSISTED SINTERING WILL BE INVESTIGATED. THE PROGRAM WILL INVESTIGATE AND DOWN SELECT THE MOST PROMISING MATERIAL SYSTEMS TO ACHIEVE NASA DEFINED METRICS USING AN OPTIMIZATION APPROACH THAT INCLUDES FABRICATION AND MATERIAL COST CONSTRAINTS. MATERIALS TO BE INCLUDED FOR DOWN SELECTION INCLUDE HIGH PERFORMANCE LIGHT METALS (ALUMINUM MAGNESIUM TITANIUM AND BERYLLIUM ALLOYS) LIGHT MULTIPLE PRINCIPLE COMPONENT (HIGH ENTROPY) ALLOYS METAL BONDED CERAMICS (TITANIUM BONDED TIB/TIB2 ALUMINUM BONDED B4C ETC) AND FIBER REINFORCED METALS (CARBON OR ALUMINA BASED FIBERS IN LIGHT METAL MATRICES). TECHNIQUES FOR THE ROBUST ATTACHMENT OF FACE SHEETS TO THESE CELLULAR STRUCTURES WILL ALSO BE ADDRESSED. THE PROGRAM WILL FOCUS ON QUARTER-SCALE COMPONENTS IN YEARS 1 AND 2 AND DEMONSTRATE HALF SCALE MULTIFUNCTIONAL PERFORMANCE BY THE CONCLUSION OF THE THIRD YEARS EFFORT.