NATIONAL HARBOR, MD -- The Air Force's replacement for the ground-based nuclear missile underwent its first wind-tunnel test and is on track to conduct its first flight tests in 2024, according to Northrop Grumman's program manager. Sentinel, formerly the Ground Based Strategic Deterrent , will replace the Minuteman III intercontinental ballistic missile -- a weapon developed more than 50 years ago. The new system reflects the advancements in technology in the past half-century by using digital engineering, advanced tooling and...