Power for hypersonic vehicles using thermionics

Implementation of onboard power sources for electronics, sensors and avionics on hypersonic vehicles while reducing weight and volume will be key to achieving successful mission profiles for reusable, attritable and exquisite systems. Survivability at high temperatures in severe shock/vibration environments is key, and harvesting high-quality heat generated during hypersonic flight utilizing a solid-state energy harvesting solution will enable significant weight savings by reducing the weight/size of batteries needed for such functions. To address this need, Spark is developing thermionic generators with novel materials, utilizing innovative manufacturing techniques to withstand the high temperature and shock environments associated with Mach > 5.0 flight conditions. The high-temperature and extremely high heat-flux environment essentially eliminates competing power generation options (e.g., thermoelectrics), but is incredibly well-matched to proven thermionic technology: thermionics can simultaneously reject ~1 MW/sq.m. of heat, while extracting ~100 kW/sq.m. of electricity within this high temperature environment. We are currently working with OEMs for survivability tests and plan to test and integrate our arrays during this Phase II into relevant propulsion system sections for harvesting waste heat to produce usable power. The AF Component for this Phase II solicitation is AFWERX and technical work will be managed by AFRL/RQ.