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The fundamentals of launch vehicle design are examined using simpli ed single-stage, two-stage, and Space Shuttle performance equations. The single-stage-to-orbit launch vehicle is very sensitive to the performancecritical parameters of mass ef ciency, propulsion ef ciency, and loss management. Cost and operations coupled in the performance equation further complicates the design process. Launch vehicle design is optimized when the performance and programmatic drivers are balanced. Programmatic drivers include affordability, reusability, operability, abort/safety, and reliability. The issues, disciplines, and potential problems that characterize the building of a future launch system are presented. The history of the Space Shuttle is used as the benchmark example. Robustness is the key to uncoupling the design factors so that optimization can occur, but typically robust designs de ne low-performance systems. Future space launch vehicles must develop new technologies to reshape the design parameter sensitivities of the robustness and performance functions. NomenclatureDMF n = dry-mass fraction, stage n [n D 1, 2 (one-usable propellant stage mass/total stage mass)] g = gravitational acceleration I sp n = speci c impulse, stage n .n D 1; 2/ = natural log m n = stage n total mass .n D 1; 2/ m o = total vehicle mass; two-stage, m o D m 1 C m 2 m p1 = usable solid rocket booster (SRB) propellant mass m ¤ = Space Shuttle main engine (SSME) propellant mass used during SRB stage n = number of stages; n D 0 references the single-stage-to-orbi t vehicle ® = 1=f1 C¯[.1 ¡ DMF 2 /=.1 ¡ DMF 1 /].m 2 =m 1 /g or m p1 =.m p1 C m ¤ / = ratio of (SSME propellant used from liftoff to SRB separation)/(total SSME propellant used from liftoff to main engine cutoff) 1V= velocity change from liftoff to orbit 1V loss = gravity losses, drag losses, etc.= .1 ¡¯C¯¢ DMF 2 / or [.m 2 ¡ m ¤ /=m 2 ]

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