A Unit-separable Earth Observation CubeSat Structure Concept Using Flat-retractable Truss Structure

Abstract

In the global aerospace industry, the demand for small satellites to verify space science technology at low cost is recently increasing. However, the payload volume is limited due to the small size of the satellite, and it affects the payload size and mission performance. To overcome this limitation, the utilization of deployable structures in space structures is gaining attention. In this study, we propose an 8U CubeSat structure concept that can be separated into upper 4U and lower 4U in orbit. A flat-retractable truss structure, which has a compact storage volume and high stiffness compared to other deployable structures, is used for separation between upper and lower units. To confirm the feasibility of the proposed structural concept, a CubeSat structure prototype is manufactured. Imaginary optical payload is assumed to be mounted and the optical performance of this concept is theoretically analyzed. In addition, a membrane shield concept in the form of an origami-based Bellows patterned cylinder is designed to prevent the light disturbance and thermal deformation of the deployable structure. Finally, the unit-separable 8U CubeSat structure integrated with the shield structure was presented.