Tentative design of constant-altitude flight subsonic solid rocket

The tentative design of constant altitude flight solid rocket composed of the sustainer ,the booster and its simple control method is presented.The rocket reaches the predicted flight velocity after the operation of booster is finished,then the sustainer starts work during which the thrust of rocket is equal to the resistance acting on the rocket,while the lift of the rocket is equal to its weight.The rocket can fly at constant speed and constant altitude.