C3S LLC

C3S LLC is a pioneering European space industry SME specializing in the design and manufacturing of 3–16U CubeSat platforms and subsystems. By adapting advanced large satellite solutions into nano-sized formats, we deliver spacecraft with exceptional longevity and reliability. Alongside CubeSats, we develop electrical power and control systems for large satellites, enabling us to operate in both the New Space and traditional space industry segments.

C3S is the only Hungarian company with CubeSat flight heritage: Masat-1 (1U), RadCube (3U), VIREO (3U), and WREN (6U). We managed development, MAIT, operations, and launch management, using our own Mission Operations Center with UHF, VHF, and S-band ground stations.

Our flagship platform, RadCube, reached TRL9 in 2021 and operated flawlessly from its launch (Aug 2021) until natural deorbiting (Aug 2024). It demonstrated miniaturized instruments for in-situ space radiation and magnetic field monitoring, contributing to real-time space weather data. The mission, part of ESA’s CubeSat fleet, helped tailor ECSS standards for nanosatellites and laid the foundation for our future platforms. Subsystems proven on RadCube are reused in upcoming missions such as MAUVE (16U, 2025), WISDOM (2×3U, 2025), and OPS-SAT ORIOLE (12U, 2026). Our VIREO (2023) and WREN (2024) satellites continued to validate these solutions.

C3S also contributes to large satellite missions. Since 2015, we have been part of ESA’s PLATO 2.0 with OHB and DLR, developing the Ancillary Electrical Unit (AEU) to power and synchronize 26 onboard cameras. We provided payload power consultation for ESA’s SMILEsxi, and advanced a TRL6 space-grade DCDC converter through ESA’s “Custom power supply development” project. We also established high-reliability electronics manufacturing competence under ESA funding. In 2022, we began GRASSHOPPER, a GaN-based resonant DCDC converter with Thales Alenia Space, targeting efficient power for satellites, HAPS, and beyond.

Beyond CubeSats and power electronics, C3S is engaged in multiple ESA and international projects. We prime the SAILOR mission for ESA’s Space Debris Office, featuring sails for debris detection. We are delivering EPS units for two small satellites, contributing a positioning subsystem for the DRACO mission, and developing ENCORE, a motor converter for a lunar lander. Under ESA ARTES, we are building CHAMELEON, a next-generation telecom satellite power supply system.

With more than a decade of experience, C3S has built a solid foundation of technical excellence, financial stability, and flight heritage. Our dual expertise in nanosatellites and large satellite systems positions us uniquely to deliver innovative, reliable solutions to clients across the global space industry.