The HIFiRE Flight 2 Experiment: An Overview and Status Update

Abstract

A collaborative international effort, the Hypersonic International Flight Research Experimentation (HIFiRE) Program aims to study basic hypersonic phenomena through flight experimentation. A number of test flights are planned, with some designated to study the operation, performance, and stability characteristics of hydrocarbon-fueled scramjet combustors. HIFiRE Flight 2 teams the Australian Defence Science and Technology Organisation (DSTO), the United States Air Force Research Lab (AFRL), and NASA. Flight 2 will develop an alternative test technique for acquiring high enthalpy scramjet flight test data, and will explore in flight Mach 8, hydrocarbon-fueled scramjet performance and dualto-scram mode transition. The generic scramjet flowpath is research quality and the test fuel is a simple surrogate for an endothermically cracked liquid hydrocarbon fuel. The HIFiRE program follows the HyShot and HYCAUSE programs and aims to leverage much of the low-cost flight test technique developed in those programs. HIFiRE Flight 2 will be a first of its kind in contribution to scramjets. It will explore suppressed trajectories of a sounding rocket propelled test article and their utility in studying ramjet-scramjet mode transition and flame extinction limits research. This paper describes the overall scramjet flight test experiment mission goals and objectives, requirements, preliminary payload design and mission, test plan and status, risks, and challenges. A successful launch and operation will present to the scramjet community valuable flight test data in addition to a new tool, and vehicle, with which to explore high enthalpy scramjet technologies. Nomenclature