Solution Manual Incropera Dewitt - Custom Course Design and Development in Engage. Wiley worked with Jack to devise a digital course solution in Wiley’s LMS platform, Engage. After conducting a needs assessment to establish a course design, we created a simplified learning path for students.. Everything about fundamental spacecraft design revolves around the Tsiolkovsky rocket equation. Δ v = V e * ln[R]. The variables are the velocity change required by the mission (Δ v or delta-V), the propulsion system's exhaust velocity (V e), and the spacecraft's mass ratio (R).Remember the mass ratio is the spacecraft's wet mass (mass fully loaded with propellant) divided by the dry mass.