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Prototype fiber optic imaging system for aerospace applications

Cameras provide excellent in situ coverage of many events of interest in current state-of-the-art aerospace systems. From departing earth footage to booster separation events, cameras provide the eyes in the skies for real-time situational awareness on the ground. One of the principal challenges of using cameras on high-speed aerospace vehicles is designing the necessary environmental protection systems to isolate the cameras from the harsh aerothermal environment. An established approach uses an external fairing or aeropod to provide the requisite isolation. The camera is located within the aeropod, and the image data are sent electrically from the aeropod to the telemetry system. While this approach has been successfully demonstrated on numerous platforms, there are advantages to moving the camera into the interior of the vehicle and reducing the size of the imaging hardware within the aeropod. If the size of the pod hardware can be reduced, multiple imaging sensors can be fit within the same aeropod. Alternatively, a smaller sensor can allow for a reduced aeropod size with commensurate reduced drag and aerothermal heating. A prototype fiber optic imaging system was developed for aerospace applications by combining a modified medical endoscope with a ruggedized camera. With this new configuration, a significantly smaller aeropod can be used to protect only the distal tip of the endoscope in lieu of the entire camera assembly. The data are acquired through a small lens at the distal tip and transmitted optically through a coherent imaging fiber bundle to a camera located within the vehicle. Data from the prototype fiber optic imaging system are compared with data acquired by a standard ruggedized camera. Results of these tests are reported in this paper.