Nearly 40% of small satellite missions fail, resulting in significant financial losses and mission setbacks due to integration failures and poor system traceability (NASA, 2024). As satellite systems become increasingly complex and time-constrained, traditional document-based systems engineering approaches are no longer sufficient to manage dynamic design requirements and subsystem interdependencies. Without scalable and adaptive methodologies, projects face increased risk of delays, cost overruns, and reduced mission success rates. The core challenge lies in fragmented documentation, limited lifecycle traceability, and delayed validation, which prevent early detection of integration issues. To address this, this study explores the Model-Based Systems Engineering (MBSE) solution space using SysML, implemented through a representative small-satellite system case study. The proposed methodology integrates structural, behavioral, and parametric models within a unified environment using Cameo Systems Modeler. Key system elements, including architecture, control logic, and constraint validation, are modeled through interconnected SysML diagrams to ensure system-level consistency. The results indicate that MBSE significantly improves design traceability, cross-subsystem coordination, and early validation, thereby reducing integration risks and enhancing development efficiency. The main contribution of this research is a scalable MBSE framework for small satellite systems that demonstrates its effectiveness in improving reliability and supporting agile, model-driven aerospace engineering.