Based on experience gathered during the Sharp Edge Hypersonic Flight Experiments SHEFEX-I and SHEFEX-II the German Aerospace Center performed the Rocket Technology Flight Experiment-Transition (ROTEX-T). ROTEX-T was successfully launched on 19 July 2016 from the Esrange Space Center near Kiruna in northern Sweden. ROTEX-T was a low-cost flight experiment mission without an inertial measurement unit, reaction control system, or parachute. The payload reached an altitude of 183km, performed a ballistic reentry with a total flight time of approximately 446s, and was afterward recovered by helicopter. A unique and modular data acquisition system with sampling rates of 20Hz, 1kHz, 10kHz, and 2000kHz was developed for ROTEX-T to study also instationary aerothermal phenomena. All flight data were transmitted via telemetry during flight or downloaded from the onboard memory units after recovery. Using the measured surface pressures and two different analyticalumerical methods, the vehicle attitude was calculated for ascent and reentry. The computations gave adequate results for the angle of attack and sideslip within the accuracy of the described methods. The measurements of the heat flux microsensors were compared with calculated values of two analytical and one numerical approaches. An overall reasonable agreement was achieved between computations and measurements for laminar and turbulent levels with deviations between 15.4 and 19.5% at maximum heating. In addition to the heat flux sensors, the heat flux was also derived from temperature measurements of coaxial thermocouples. For the first 33s of the ascent phase, the derived heat fluxes agreed well with measurements of the heat flux microsensors to within 0.8-5% at maximum heating levels. After that instant of time, the heat fluxes start to differ significantly due to violation of the semi-infinite wall assumption and thermocouple heating by transversal conduction.
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