Cube1G: a full-hemispherical, high-speed optical communication terminal for CubeSats

Kurzfassung

The growing demand for high-speed free-space optical satellite communication requires compact designs that operate independently of satellite attitude constraints. Cube1G, developed by the German Aerospace Center (DLR) Institute of Communications and Navigation (IKN), is a novel laser communication terminal that combines coarse and fine pointing mechanisms, allowing hemispherical beam steering independent of the satellite’s orientation. With a compact volume of two units plus a “tuna can”, Cube1G is designed for a wide range of missions, including satellites with limited attitude control, such as CubeSats, Earth observation platforms with strict payload orientation needs, and high-data-rate communication networks. The system supports 100 Mb/s inter-satellite links and 1 Gb/s space-to-ground connections. Its first in-orbit demonstration on the SeRANIS mission in 2026 will validate its performance and enhance the satellite’s data transfer capabilities for scientific and operational payloads. This paper presents the design of the Cube1G terminal, expected in-orbit performance, and results from ground-based tests and qualification before its integration on the ATHENE 1 small satellite. Cube1G aims to support the development of flexible optical communication architectures and advance toward the next generation of satellite networks.