Introduction The Defense Advanced Research Projects Agency (DARPA) has unveiled an ambitious new initiative—the Series Hybrid Electric Propulsion AiRcraft Demonstration (SHEPARD) program, designated as the XQ-73. This “X-prime” program builds upon previous advancements from the Air Force Research Laboratory (AFRL) and Intelligence Advanced Research Projects Activity (IARPA) under the Great Horned Owl (GHO) project, which…

