A novel design of a deployable CubeSat for material exposure missions in low earth orbit

As an important subject of space technology, material exposure experiments provide data not only for material selection in spacecraft design but also for new materials research and development. It is usually expensive and time-consuming to carry out traditional missions of material exposure experiments on large space vehicles, such as space stations or satellites. Therefore, in this paper, a CubeSat-based platform is proposed to accelerate this type of mission cycle. Within the 3U envelope of CubeSat, a design strategy of a deployable structure is adopted to enlarge exposable surfaces. This strategy enables a reconfigurable architecture to meet the size and volume requirements during the launch stage and increase the areas to be exposed in space by up to 40%. The degradation statuses of the material samples are directly monitored by an optical camera. To ensure sufficient coverage of the visual field, a differential rotation mechanism is designed to drive petaloid double-layer sample trays. Graphic data of samples may be transmitted to the ground in a timely manner at a proper orbital altitude. Thermal and modal analyses for Material Exposure CubeSat (MEC) are also included in this paper. Finally, a 3D-printing prototype is manufactured to examine the feasibility of the differential rotation system and visual coverage of sample trays. Overall, the MEC proposed in this paper exhibits a novel platform to conduct material exposure experiments in space with the advantages of low development cost, short production cycle and portable volume.