American Institute of Aeronautics and Astronautics 092407 1 SpaceNet: Modeling and Simulating Space Logistics Gene Lee * , Elizabeth Jordan † , and Robert Shishko ‡ Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, 91109 Olivier de Weck § , Nii Armar ** , and Afreen Siddiqi †† Department of Aeronautics and Astronautics, Massachusetts Institute of Technology, Cambridge, MA, 02139 This paper summarizes the current state of the art in interplanetary supply chain modeling and discusses SpaceNet as one particular method and tool to address space logistics modeling and simulation challenges. Fundamental upgrades to the interplanetary supply chain framework such as process groups, nested elements, and cargo sharing, enabled SpaceNet to model an integrated set of missions as a campaign. The capabilities and uses of SpaceNet are demonstrated by a step-by-step modeling and simulation of a lunar campaign. I. Introduction HE term “supply chain” has traditionally been used to refer to terrestrial logistics and the flow of commodities in and out of manufacturing facilities, warehouses, and retail stores. Rather than focusing on local interests, optimizing the entire supply chain can reduce costs by using resources and performing operations as efficiently as possible. There is an increasing realization that future space missions, such as the buildup and sustainment of a lunar outpost, should not be treated as isolated missions but rather as an integrated supply chain. Supply chain management at the interplanetary level will maximize scientific return, minimize transportation costs, and reduce risk through increased system availability and robustness to failures. 1,2 SpaceNet is a model with a graphical user interface (GUI) that allows a user to build, simulate, and evaluate exploration missions from a logistics perspective. 3 The goal of SpaceNet is to provide mission planners, logisticians, and system engineers with a software tool that focuses on what cargo is needed to support future space missions, when it is required, and how propulsive vehicles can be used to deliver that cargo. Users can model space missions as interplanetary supply chains to identify, quantify, and evaluate the key drivers and logistics strategies that impact their physical feasibility and performance effectiveness. The space logistics modeling framework of nodes, processes, elements, and supplies was previously introduced in 2006 1 and has since evolved into functional versions of SpaceNet. SpaceNet v1.3, the last version officially documented in literature, 3 was used in the second Constellation Program (CxP) Integrated Design Analysis Cycle (IDAC-2). 4,5 The studies, trading launch architectures and propellant types, used a version of SpaceNet that was primarily developed to model individual, sortie-style missions. When SpaceNet was proposed to analyze the lunar campaign from a logistics perspective in the CxP IDAC-3 6 , it required fundamental upgrades in order to model such campaigns and to evaluate trades of interest. The implementation of these upgrades, and the resulting expansion in modeling capabilities, yielded SpaceNet v1.4. This paper provides a general overview of the SpaceNet v1.4 model, focuses on its current capabilities, application to campaign analysis, verification and validation status, and concludes with recommendations for future work. * Staff Engineer, Mission Systems Concepts, JPL, 301-180, AIAA Member. † Associate Engineer, Mission Systems Concepts, JPL, 301-180, AIAA Member. ‡ Principal Engineer, Mission Systems Concepts, JPL, 301-180, AIAA Member. § Associate Professor, Aeronautics and Astronautics, MIT, 33-410, AIAA Member. ** Graduate Research Assistant, Aeronautics and Astronautics, MIT, AIAA Member. †† Graduate Research Assistant, Aeronautics and Astronautics, MIT, AIAA Member. T