Legacy refractory materials that have origins dating to the original Saturn program are commonly used in current launch facilities. Although they fail to meet the target requirements, they are the only approved material. Our research team has demonstrated a baseline system during the Phase I effort that combines a non-cement binder, a high temperature macro aggregate, and reactive nano aggregates to produce an Ultra High Temperature Refractory (UHTR). Our UHTR system has sustained short term exposures to 3000C in a laboratory test and excellent resistance to environmental aging. The Phase II effort will optimize the mechanical and thermal behavior based on rocket plume exposure testing.