Long Duration Hypersonic Flight Experiment ATHEAt

The long duration hypersonic flight experiment ATHEAt was carried out with a two-stage sounding rocket configuration from the Andøya Space launch site on 6th October 2025 in Norway. The first stage motor Red Kite combined with the Black Brant Mark IV motor as the second stage made it possible to fly a payload with a mass of 244 kg at Mach numbers between 5.0 and 9.46 at an altitude range from 18 to 31 km for 119 s. The forebody of the scientific payload features a thermal protection system (TPS) made of ceramic matrix composite (CMC) segments. The first part has an ogive shape followed by an octagonal shape and four flaps. The payload includes a transpiration cooling and an impingement cooling experiment. The initial 5 deg deflection of all four flaps was increased to 20 deg during the hypersonic flight phase. In addition to 370 intrusive sensors, additional nonintrusive techniques were used for the measurement of displacement and deformation of hot structures. Two infrared (IR) cameras and four pyrometers measured the surface temperature distribution of the flap rear surfaces. To minimize the apogee dispersion and enable precise science conditions for the flight experiment, a flight-qualified predictor was used.