Photos: Atlas 5 on the pad awaiting liftoff on NROL-52

Bulking up NASA’s constellation of tracking stations in the sky that provides critical links between orbiting spacecraft and ground control, a United Launch Alliance Atlas 5 rocket successfully deployed a new communications hub in space today.

Rolling toward a mid-May deployment of a clandestine spy satellite, United Launch Alliance’s triple-body Delta 4-Heavy rocket moved from its Cape Canaveral assembly building to pad 37B yesterday.

United Launch Alliance will need to lure commercial customers to ensure the economic viability of its new Vulcan rocket, which is set to debut in 2019 just as the rate of U.S. military satellite launches is due to take a dip.