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2. Verfahren zum bergen einer stufe eines mehrstufigen raumtransportsystems (DE 101 47 144 C1 2003).
3. M. Sippel, S. Singh, S. Stappert, RLV-Return Mode “In-Air-Capturing” and Definition of its Development Roadmap, in: 9th European Conference on Aeronautics and Space Sciences, EUCASS, 2022.
4. S. Stappert, J. Wilken, L. Bussler, M. Sippel, Innovative Method for Return to the Launch Site of Reusable Winged Stages, in: International Astronautical Congress, 2019.
5. S. Stappert, J. Wilken, G.J.C. Dominguez, M. Sippel, Evaluation of Parametric Cost Estimation in the Preliminary Design Phase of Reusable Launch Vehicles, in: 9th European Conference on Aeronautics and Space Sciences, EUCASS, 2022.