Reentry CubeSat Heatshield Monitoring System Using Fiber Bragg Gratings

Abstract

In space applications, CubeSats are used for all kinds of commercial and research purposes. These small satellites are launched in such large numbers that from a pollution point of view it makes sense to return them intact to Earth. To establish this, a dedicated reentry is needed. During this reentry process, the CubeSat has to make use of a heatshield which deforms due to multiple forces acting upon the structure. In order to monitor this heatshield, this study aims at investigating, designing, simulating, and testing the integration and readout of fiber Bragg gratings (FBGs) into a mock-up heatshield, in order to monitor its shape. Therefore, a mock-up of a CubeSat and its accompanying heatshield is constructed to simulate the realistic use of FBGs. Based on the external dimensions of the heatshield, the study gives a practical installation pattern for the FBGs. A 3-D simulation model of the heatshield and accompanying CubeSat is built. To achieve deformation in this 3-D model, the study proposes an algorithm based on single-point data. Using existing OROCOS/ROS middleware, the study establishes a comprehensive system for setting up and reading out FBGs in order to gather information on the heatshield’s status. Finally, after testing the mock-up heatshield set, the system can reflect the deformation of the heatshield in real-time in the 3-D model. Additionally, the system can save the entire deformation process of the heatshield as a series of model files, which can be used for sophisticated static analysis.