Probe rocket
A sounding rocket is a small rocket that carries instruments for studying the Earth's upper atmosphere or for making astronomical observations from above the atmosphere. A sounding rocket, unlike a launch vehicle, does not enter orbit, generally its flight follows a parabolic trajectory describing a suborbital flight.
Rockets are used to carry instruments from 50 to 1,500 kilometers above the earth's surface, generally the altitude between weather balloons and satellites. Some sounding rockets, such as the Black Brant X and XII, have an apogee between 1000 and 1500 kilometers, the peak of its class. Sounding rockets often use military surplus rocket motors.
Design
A common sounding rocket consists of a solid-fuel rocket motor and a scientific payload. The free-fall portion of the flight is an elliptical path with the major axis vertical, which allows the payload to appear to be hovering nearby. from its peak. Average flight time is less than 30 minutes, generally between five and twenty minutes. The rocket burns its fuel in the first stage of the ascending part of the flight, then separates and falls, leaving the payload to complete the arc and return to the ground with a parachute.