Abstract: Concerning requirements for the onorbit release and separation of nanosatellitefractionated payloads, a design of the springloaded separation system is presented. It is aimed at the problem that the international commercialofftheshelf products are inadaptable for the nonstandard ratio of weight and volume. The separation system is able to support 6 U (1 unit = 1 dm3 volume) and 10 kg payload. Taking into account the design constraints, the plan consists of the central bearing frame, separation mechanisms and the docking ring. Modal and acceleration loading analyses are carried out.  Accordingly the onorbit simultaneous separation process of two opposite ones is presented. Analyses results show that the structural design meets the requirement for launching. The designed plan serves as an effective and applicable solution for the mission.

Key words: nanosatellite, fractionated payloads, separation system, structural design and analysis