AFRL Leads Falcon HTV-1 Model Tests Published Dec. 12, 2006 By Plans and Programs Directorate AFRL/XP WRIGHT-PATTERSON AIR FORCE BASE, Ohio -- The Falcon program, a joint effort between Air Force Space Command and the Defense Advanced Research Projects Agency, is an initiative focused on developing and validating technologies needed for prompt global reach while demonstrating affordable and responsive spacelift. The in-flight technologies undergoing maturity as part of this effort range from manufacturing technologies (including those enabling low-cost expendable launch vehicle concepts) to reentry technologies (including thermal protection materials and guidance and navigation systems). AFRL researchers led the first Falcon Hypersonic Technology Vehicle (HTV-1) model wind tunnel tests. They conducted these tests to investigate localized aerodynamic heating and validate the accuracy of computational fluid dynamics (CFD) predictions. HTV-1 represents the first of three vehicle designs to be examined under the Falcon program. Engineers from AFRL and Falcon prime contractor Lockheed Martin identified six HTV-1 flight configurations for experimental validation. The National Aeronautics and Space Administration (NASA) Langley Research Center manufactured six models representing these configurations. The models consisted of a ceramic base coated with phosphor paint, which when heated and exposed to ultraviolet light, emits radiant energy proportional to the model's surface temperature. During testing in the Mach 10 wind tunnel at NASA's Langley site, a charge-coupled device camera recorded the models' respective heating patterns. Engineers used this recorded data to verify corresponding CFD predictions. The entire process--from initiation through testing--took less than 2 months, a testimony to the team's skill.