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Collaborative optimization is a new design architecture specically created for large-scale distributed-analysis applications. In this approach, a problem is decomposed into a user-dened number of subspace optimization problems that are driven towards interdisciplinary compatibility and the appropriate solution by a system-level coordination process. This decentralized design strategy allows domain-specic issues to be accommodated by disciplinary analysts, while requiring interdisciplinary decisions to be reached by consensus. The present investigation focuses on application of the collaborative optimization architecture to the multidisciplinary design of a single-stage-to-orbit launch vehicle. Vehicle design, trajectory, and cost issues are directly modeled. Posed to suit the collaborative architecture, the design problem is characterized by 95 design variables and 16 constraints. Numerous collaborative solutions are obtained. Comparison of these solutions demonstrates the inuence which an a priori ascent-abort criterion has on development cost. Similarly, objective-function selection is discussed, demonstrating the dierence between minimum weight and minimum cost concepts. The operational advantages of the collaborative optimization architecture in a multidisciplinary design environment are also discussed.Aerospace Engineer, Senior member AIAA. y Aerospace Engineer, Senior member AIAA. z Associate Professor, Senior member AIAA.

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The primary objective of the Mars Path nder mission was to demonstrate an innovative, low-cost, reliable method for placing a science payload on the surface of Mars. The spacecraft performance during entry, descent, and landing is assessed. Analysis of the accelerometer and altimeter ight data obtainedby the Path nder spacecraft during atmospheric ight is provided. Results of an effort to reconstruct the spacecraft trajectory and attitude history are presented. An estimate of the Mars atmosphere pro le encountered during atmospheric ight is given. ½ = atmospheric density, kg/m 3 ! obs = observed vehicle roll rate, rad/s ! z = roll rate about the vehicle Z axis, rad/s