Rapid Ultraviolet LED Tester for Space Materials

Space Technology is critical to the US government’s and AFRL’s long-term strategic direction. Ultraviolet (UV) light is both a cause of damage and degradation to space materials and an emerging opportunity to increase solar power production in space. Better UV test capability will improve spacecraft survival and increase power generation capability in the UV-rich space environment. With the improvement in satellite technology, we are seeing a shift from a small number of large satellites to many smaller satellites. The DoD plans to fly a lot of satellites soon. Many tasks formerly performed by a single, large satellite in geosynchronous orbit will soon be performed by constellations of hundreds of smaller satellites closer to Earth. The Space Defense Agency has contracted with prime contractors to build and launch several tranches of large quantities of satellites. The Air Force and Space Force have similar plans for proliferated constellations of smaller satellites for many future programs. Increasing power generation and material UV survivability increases the capabilities of all future satellites. More power and better materials give satellites greater power, more maneuverability, and smaller solar panels for enemies to target. Higher power through better capture of UV energy in sunlight will improve all future satellites, which supports every future mission. Solar cell manufacturers are pursuing wider bandgap junctions to make use of the UV wavelengths. This requires UV improvements in many materials, including cover glass, adhesives, and the solar cell materials themselves. Testing capability is needed to build this better future.  The primary need is for accelerated UV degradation testing. UV is a future opportunity, but is presently, largely, a plague on power systems. Being able to see how cells, adhesives, or cover glass hold up is critical. Being able to provide more UV light speeds up testing. Accelerated UV test is important for calculating lifetime of all space materials, particularly solar cells. The key objectives of this program are:Develop a prototype, UV LED tester for performing UV soak degradation testingMeasure the performance of the new UV tester, including power output, spectral output, uniformity, temporal stability, and light source degradationDeliver the hardware to the government for evaluation, testing, and use.Make the UV tester commercially available to the US government and its commercial supply chainThis project will develop 2 prototypes of an LED-based UV tester. Goals include 3.5x suns, of the 250nm – 400nm portion of the AM0 spectrum, with the 1st prototype using a single pLEDss head for small-area evaluation and the 2nd prototype using 6 pLEDss heads for a larger-area study. Each prototype will be evaluated to determine performance and then delivered to the government. Prototypes will be developed with post-contract commercialization in mind.