WASHINGTON — A SpaceX Falcon 9 rocket lifted off April 2 at 10:29 a.m. Eastern from Launch Complex 4 East at Vandenberg Space Force Base, California, carrying 10 military satellites, including two built by SpaceX. The mission to low Earth orbit is the first launch of a new military communications and missile tracking constellation built by the Space Development Agency (SDA), a U.S. Space Force organization created to accelerate the use of commercial space technologies in military systems. SpaceX first attempted to launch this mission March 30 but the launch was aborted three seconds before liftoff. The company said the...