Description: NASA has long used liquid hydrogen as a fuel and plans to continue using it in association with their advanced nuclear thermal propulsion technology. Hydrogen fire detection is critical for rocket propulsion safety and maintenance. A significant fire at a rocket test or launch facility could be catastrophic to infrastructure or even worse, to human life. Detection monitoring is problematic as hydrogen flames can be nearly invisible during the day. Non-imaging, Non-visible fire detection technology has limited range and can suffer from false alarms from sources outside the region of interest. Low-cost visible imagers, commonly used for wide-scale routine surveillance, have limited utility detecting hydrogen fires. Although it has been known for decades that multispectral imaging outside the visible range can be used to detect fires with low false alarm rates, the price of such systems and the lack of processing algorithms and ability to implement them in real-time has largely prohibited their use. During this project we will develop a low-cost imaging capability that fuses data collected from sensors operating in the (1) solar blind ultra-violet, (2) thermal infrared, (3) mid-wave infrared, and (4) visible spectrum, using advanced spectral, spatial and temporal processing techniques optimized to detect and generate alerts associated with hydrogen fires in real-time. This multi-sensor, multi-processing approach will enable us to automate flame detection with extremely low false alarm rates. This multisensory imaging research could also support NASA's important cool flame microgravity research occurring on the International Space Station.

Benefits: This technology has near term direct application for monitoring hydrogen fires within several NASA propulsion test and launch facilities. This capability will enhance the safety of these facilities and potentially facilitate required maintenance procedures. NASA rocket motor testing centers that would benefit from this include SSC, MSFC, GRCPBS and WSTF. KSC, responsible for the SLS and Orion launches that continue human spaceflight within NASA, and the Launch Services Program that provides launch operations oversight at several locations including Cape Canaveral Air Force Station and Vandenberg AFB would also realize safety and maintenance benefits from this technology. NASA is currently conducting experiments on flame interaction and extinguishment onboard the ISS. Fire burns differently in microgravity and although our technology is optimized for hydrogen flame phenomenology, it has wider potential use in NASA's cool flame research portfolio and could, for example, be used to support follow-on Saffire and FLEX experiments. FLEX experiments have shown low-frequency flicker that our temporal algorithms could exploit for terrestrial fire detection and discrimination.

Government facilities managed by the Rocket Propulsion Test Program Office, including Arnold Engineering Development Center (AEDC), Redstone Test Center (RTC), the Air Force Research Laboratory (AFRL) and the Naval Air Warfare Center (NAWC) as well as commercial facilities including SpaceX, Blue Origin, Sierra Nevada Corporation and Orbital ATK could all enhance their safety and facilitate their maintenance efforts by employing this technology to monitor hydrogen and other flames. There are several established markets and applications that incorporate significant amounts of hydrogen gas in their processes that would benefit from our flame detection technology. These markets primarily include petrochemical facilities, heat treating facilities for aerospace and automotive applications, fuel cell production facilities, food processing facilities (for hydrogenation) and potentially thermonuclear power plants. An emerging application is hydrogen fuel cell fueling station monitoring. With the advent of fuel cell powered vehicles, hydrogen fueling stations will be required along roadways as a way of refilling fuel cells. These fueling stations are required by law to include hydrogen flame sensing technology.