Live coverage: Kennedy Space Center to reopen Friday

SpaceX has slowed development of the Falcon Heavy rocket, a mega-booster made of three Falcon 9 booster cores strapped together, as the company recovers from a launch failure last month, delaying the new rocket’s debut until early 2016.

The United Launch Alliance Delta 4-Heavy rocket, standing 235 feet tall and weighing 1.6 million pounds fully fueled, unleashes 2.1 million pounds of thrust from the three RS-68A main engines at 1:51 p.m. EDT (1751 GMT) today to launch from Cape Canaveral on NROL-37.

The ubiquitous Global Positioning System that ties the space program to everyday life on Earth, providing precise navigation to the world through a constellation of orbiting satellites, will be strengthened courtesy of a new craft launched Wednesday.