Flown, this bell-shaped retrorocket stands approximately 9" tall with a diameter of 7" at its widest point.

The main function of a retrorocket is to provide thrust opposing the flight motion of a spacecraft, slowing down the aircraft, and thereby decreasing its altitude. Retrorockets are absolutely essential for orbital spacecraft, and are also useful for touch down on other planets or the moon. Approaching touch down on the moon, after the heat shield has been released just a few feet from the surface, small engines on the base of the landing module fire. A retrorocket such as this will fire just before touchdown, easing the landing for astronauts, or in the case of this particular specimen, cosmonauts. This particular Soyuz retrorocket was designed to fire just seven feet above the surface of the earth upon reentry in order to help soften the landing for the Russian cosmonauts inside the aircraft. One of these Soyuz rockets currently resides at the Smithsonian Institution's National Air and Space Museum. Two valves at the top of the rocket presumably connect to the electrical supply of the Soyuz spacecraft. Typical scoring and wear. A fascinating piece of Russian space history.