HIFiRE 0 Flight Test Data

The objective of the Hypersonic International Flight Research Experimentation (HIFiRE) program is to increase understanding of fundamental hypersonic phenomena and to develop technologies deemed critical to the realization of next generation aerospace vehicles. The aim is to develop the necessary technologies for prototyping a scramjet-powered, free-flying autonomous vehicle capable of sustained level flight. The purpose is to extend the hypersonic database and enhance the accuracy of complex models and simulations. The product will be an experimental flight laboratory to capture extensive coherent high-fidelity data. HIFiRE 0 served as a risk-reducing, systems-proving protoflight for the fundamental science payload, HIFiRE 1. Both payloads are launched on highly parabolic trajectories, reminiscent of the HyShot trajectory, requiring an exo-atmospheric attitude manoeuvre to reorient the payloads for a nose-down re-entry. This trajectory was achieved using a Terrier-Orion two-stage rocket motor stack. HIFiRE 0 was a low cost payload that provided valuable data regarding the performance of on-board systems such as horizon sensors, magnetometers, accelerometers, cold gas thrusters, launch lug, flight computers and crucially, the flight software. HIFiRE 0 tested approximately 60% of all new subsystems required to complete the HIFiRE program. In line with HIFiRE 0's primary goal of proving the onboard sensing and control systems, a simplified geometry with minimal additional sensors had been adopted. A slightly simplified version of the HIFiRE 1 service module was located at the rear of the payload and contained vital sensors and hardware. It formed the base of the payload, to which a 3:1 ogive nosecone was rigidly attached. The nosecone remained attached throughout the flight and the only additional instrumentation that it contained was a pair of pitot probes for high and low pressure ranges. They were installed at the blunted nosetip. The HIFiRE 0 payload was assembled, ground-tested and then launched in early May 2009. It contained major upgrades not incorporated on the previously flown HyShot/HyCAUSE payloads. These upgrades included: new flight computers; a newly developed operating system; new flight software; a more robust algorithm for controlling the reorientation manoeuvre; and a modified telemetry system. A tertiary experiment that had the potential to further enhance the value of HIFiRE 0's flight included thermal paints at selected locations on the external surface of the payload and on the internal surface of the thinwalled nosecone. This paper presents flight data from the on-board sensors and evaluates the performance of the control systems.