FAIRFIELD-SUISUN, CALIFORNIA A model of a hypersonic vehicle is tested Dec. 10, 2009, at NASA’s Langley Research Center, Maryland. (Courtesy file photo (2009)) Department of Defense unveils hypersonics development plan By Department of Defense News WASHINGTON, D.C. — The Defense Department has identified hypersonics as one of the highest priority modernization areas, as Russia and China develop their own capable systems. Hypersonic systems are able to travel on extended flights within the upper atmosphere – 80,000 to 200,000 feet – at speeds near and above Mach 5, and they’re able to maneuver in ways that are hard for defenders to predict. The high-altitude range creates a gap between air defenses and ballistic missile defenses, said Mike White, principal director for hypersonics in the office of the undersecretary of defense for research and engineering.