Show that if engine mass were a negligible part of the entire total mass of a rocket vehicle, and if the total structural and engine mass were simply proportional to the initial mass, the structural efficiency factor would be independent of the mission Au. A single-stage solid propellant booster has the following characteristics: Mengine = 0.005, tank = 0.03, prop Isp = 200. Show how the payload ratio and the structural efficiency depend on the mission velocity Au. The definition for structural factor in this case may be written as E = tank + Mengine Mprop tank + Hengine Neglect gravity and drag effects.