STUDY OF COSMIC REIONIZATION HAS BEEN HIGHLIGHTED BY THE LAST DECADAL SURVEY AS ONE OF THE MOST PROMISING AREAS OF ASTROPHYSICAL RESEARCH IN THE CURRENT DECADE. COSMIC REIONIZATION ON COMPUTERS (CROC) PROJECT AIMS AT TAKING ADVANTAGE OF THE RECENT TECHNOLOGICAL ADVANCEMENT IN SUPERCOMPUTERS TO SIGNIFICANTLY IMPROVE ON THE FIDELITY AND PHYSICAL REALISM OF NUMERICAL SIMULATIONS OF REIONIZATION. CROC SIMULATIONS ARE FULLY SELF-CONSISTENT COSMOLOGICAL SIMULATIONS THAT INCLUDE A WIDE RANGE OF PHYSICAL EFFECTS FROM THE DYNAMICS OF DARK MATTER AND COSMIC GAS TO RADIATIVE TRANSFER STAR FORMATION AND STELLAR FEEDBACK. THIS PROPOSAL REQUESTS SUPPORT FROM NASA TO MAKE DETAILED THEORETICAL PREDICTIONS FOR SEVERAL OBSERVATIONAL PROGRAMS PLANNED FOR JAMES WEBB SPACE TELESCOPE (JWST) FROM LARGE-SCALE DISTRIBUTION OF HIGH REDSHIFT GALAXIES TO THE DETAILED PROPERTIES OF STELLAR POPULATIONS INSIDE INDIVIDUAL SOURCES OF REIONIZATION. BY DIRECTLY SUPPORTING THE JWST SCIENCE THIS PROJECT ALIGNS WELL WITH THE OBJECTIVES OF THE ATP PROGRAM AND TO THE MAIN NASA SCIENTIFIC INTERESTS IN ASTROPHYSICS AND COSMOLOGY.