The Pentagon is moving too slowly in its pursuit of a space-based sensor system for missile defense, the head of U.S. Strategic Command argued this week, as the Missile Defense Agency's latest budget forecasts plans to spend billions more on ground-based radars instead. MDA has a concept to develop a space-based sensor layer for tracking ballistic missiles in the midcourse phase of flight, but "we're struggling to get started with it," Gen. John Hyten, head of STRATCOM, said Feb. 28...