20 minutes, you need to practice the horizontal mode.
In the horizontal mode two string with rope handles and collision pads are pulled apart which shoots the rocket forward. It should travel toward and away from the audience to hear the Doppler shift.
In the circular mode the rocketis swung over your head.
The handles resemble those used for kite flying. The rubber cylinders are to soften the impact. There are 30 m of rope. Note the switch on the rocket.