Optical Fiber Grating Sensor Network Basing on High-Reliable Fibers and Components for Spacecraft Health Monitoring

摘要

A fiber Bragg grating (FBG) sensor network has been developed for structural health monitoring on board or the X-38 spacecraft, the prototype of a crew return vehicle for the International Space Station. The FBG sensors will monitor mechanical and thermal load profiles of a frame component during launch and re-entry of the spacecraft. Four sensor pads are interrogated which contain three Bragg gratings each for 2-dimensional orthogonal strain and temperature measurements. The requirements for mechanical and thermal stability under the demanding conditions of vibration and shock loads, at temperatures within -40..+200 °C, have been fulfilled applying appropriate fiber passivation and Ormocer re-coating techniques, and by the development of a robust polychromator based signal processing unit.