A rocket is an aircraft which is propelled forward by the reaction force produced by the working medium of rocket engine. It carries all propellants and does not rely on the external working medium to generate thrust. It can fly in the dense atmosphere or outside the dense atmosphere. It is a vehicle for space flight.
The rocket includes the structure of the rocket body, the power plant, the stable tail and so on. Most sounding rockets are single-stage or two-stage, and some are 3-stage or 4-stage. Solid rocket motor is usually used for power plant, which can simplify and shorten the launching operation time.
The requirements of attitude and trajectory of sounding rocket are not as strict as that of missile and launch vehicle. Generally, there is no control system, and flight stability is ensured only by stabilizing the tail or rotating the rocket around the longitudinal axis. Set up the control system only when precise positioning and orientation are required.