In late 2006, NASA acquired a Predator B unmanned aerial system for civilian earth science and to test out new aeronautical technologies. And since then, Ikhana has been hard at work collecting atmospheric data and providing real-time fire imaging and mapping. Its current task is to help evaluate a new system to sense wing shape and structural load.
Healthy Planes, Smart Sensors
The goal of real-time condition and health monitoring for aircraft isn't a new one: what's changed are the kinds of technologies being applied. A short list of relevant projects would include MicroStrain's helicopter pitch link that measures the real-time stresses applied to the rotor component, research into jet engine health monitoring conducted at Oxford University, the US Air Force's Integrated Systems Health Management project, and ARINC's Aircraft Condition Analysis and Management System (ACAMS), being developed with NASA's Langley Research Center. The goal is the same: measure what's happening to the aircraft so you can figure out when it's healthy and fit to fly and when it isn't. Currently, aircraft undergo preventive maintenance, swapping out parts before they fail, whether the parts need to be replaced or not. None of these projects would work without robust sensors, powerful processing, and efficient communications.
Testing Out New Technology
Ikhana's current project uses fiber-optic sensors applied to its wings to measure the strain experienced by the wing while the aircraft is in flight. The aim is to measure the shape of the wing while the aircraft is airborne. According to Lance Richards, lead for NASA Dryden's Advanced Structures and Measurement group, as quoted in the news release, "The sensors on Ikhana are imperceptibly small because they're located on fibers approximately the diameter of a human hair. You can get the information you need from the thousands of sensors on a few fibers without the weight and complexity of conventional sensors. Strain gauges, for example, require three copper lead wires for every sensor."
If the sensors work as hoped, the technology may aid in the development of active wing shape control and other aircraft structural health monitoring. (For more about the sensors, read NASA's article "Measuring Up to the Gold Standard.")