Nuri-Derived SmallSat-Dedicated Launch Vehicle: Staging Design, Vehicle Sizing, and MDO-Based Feasibility Assessment

The increasing demand for SmallSats requires launch systems providing responsive, independent, and mission-specific access to orbit. This study presents the conceptual design and feasibility assessment of a Nuri-derived SmallSat-dedicated launch vehicle for delivering a 500 kg-class payload to a 500 km sun-synchronous orbit. Unlike previous planning-level studies focused on development strategies, this study quantitatively derives a vehicle configuration through staging design by incorporating geopolitical constraints on launches from the Naro Space Center, Nuri technological heritage, and emerging upper-stage engine and lightweight structural manufacturing technologies. The required velocity increment was distributed between stages, and the preliminary configuration was established through vehicle sizing. The design was evaluated using an ASTOS-based multidisciplinary design optimization framework integrating trajectory optimization, aerodynamic analysis, flight-load evaluation, and load-bearing structural mass estimation. The optimized trajectory satisfied the target-orbit and range-safety constraints and yielded a payload capability of 530 kg. The estimated dry masses of the first and second stages were 4,051 kg and 648 kg, corresponding to structural indices of 8.7% and 12.1%, respectively. These results support preliminary feasibility under the adopted modeling assumptions at the conceptual stage rather than providing detailed design verification of subsystems, while further validation is required to address structural and subsystem mass uncertainties.