From 0 to 1200 km/h within one second: Supersonic!

posted in: General, Rockets | 0

After waiting a long time we did it finally: The first supersonic flight of a rocket of the TU Wien Space Team was performed successfully.

AirframeLOATake-off weightMotorFlight altitude, barometricmax. GNSS-fix above groundmax. velocity (via Accelerometer)max. acceleration (via Accelerometer)
STR06162 cm3776gK11002237 m
(sim. 2348 m)
2212 m391 m/s
(sim. 397 m/s)
31 g

With a maximum acceleration beyond 30g, comparable to The Hound, the rocket was accelerated to a velocity of 390 m/s within 1.4 seconds. The real airspeed could only be determined via integration of the accelerometer data due to the lack of a absolute velocimeter.

STR06_K1100_acc_airspeed

Amongst other data, we were especially interested in the measured evolution of the pressure, measured by a commercial barometer. In the following diagram, the measured pressure is shown besides the estimated airspeed.

A pressure drop is clearly visible while approaching and exiting the transonic region. Nevertheless, the apogee-detection of our boardcomputer was capable of determining the apogee perfectly and the rocket was recovered smoothly: A reefed parachute was deployed by a blackpowder charge at apogee, while the main parachute was released by the ChuteRelease at a save height. The reduced descent velocity on the main parachute can be seen in the following diagram.

str06_k1100_height_mach