The Defense Department today plans to put in orbit new space capabilities -- including a pair of competing prototype satellites built by L3Harris Technologies and Northrop Grumman -- that aim to solve one of the U.S. military's most vexing and pressing technical challenges: how to detect and track hypersonic glide vehicles that exploit blind spots in today's radar networks. A SpaceX Falcon 9 rocket is loaded for launch later today with a pair of Hypersonic and Ballistic Tracking Space Sensor...