2. A two-stage launch vehicle is to deliver a payload from the surface of the earth to LEO. Assume: Payload m = 15,000 kg Required total AV to LEO AV = 10.0 km/s First stage: jet fuel (RP-1) + liquid oxgen (LOX), Isp = 300 s structural factor, = 0.07 Second stage: liquid hydrogen (H2L) + LOX, Isp = 450 S structural factor, = 0.05 If the first stage provides a AV = 4.0 km/s, determine: (a) The payload ratios for each stage, and , as well as the overall payload ratio, .. (b) The initial mass of each stage, mos and moi. (mor = mo, the total mass prior to launch.) (c) The empty ("structural") mass for each stage, ma and ms. (d) The propellant mass for each stage, mp2 and mpi. (Hint: start with the second stage and follow the order shown above.)