Undersecretary of Defense for Research & Engineering Heidi Shyu meets with Maj. Grover Smith of the Indiana National Guard during Technology Readiness Experimentation (T-REX) 2023 at Camp Atterbury, Ind. T-REX is a critical component of the Rapid Defense Experimentation Reserve (RDER) effort, which facilitates modernization efforts through rapid prototyping and experimentation of integrated joint military technologies. (Defense Department photo).