This course is the first part of a two-semester, team-based, multidisciplinary senior design sequence. Students work in teams of three to five members, typically drawn from multiple disciplines (e.g., engineering, computer science, cybersecurity, aviation, or related fields), to define, plan, and formally propose a comprehensive capstone project. Student teams select a project and develop a thorough understanding of the project scope, including background research and documentation of related work. Teams prepare a feasibility study; develop project requirements, constraints, and performance criteria; and establish appropriate engineering, computing, software, and/or security specifications as applicable. Multiple solution concepts and design alternatives are proposed, analyzed, and evaluated using appropriate analytical, modeling, or simulation techniques. Based on this analysis, each team selects a final proposed design. Throughout the course, students are expected to apply systems engineering principles, project management practices, and effective team collaboration, including task allocation, scheduling, risk assessment, and interdisciplinary integration. Each team prepares and delivers a Preliminary Design Review (PDR) and submits a Final Project Proposal that documents the approved project scope, requirements, constraints, design approach, and implementation plan to be carried forward into Senior Design II. A comprehensive written report is submitted at the end of the semester. Additional components or discipline-specific requirements may be included depending on the nature of the project. Note: This course must be completed with a grade of "C" or higher to enroll in SDE 458 - Senior Design II.