Live coverage: Atlas 5 countdown and launch journal

Culminating years of construction and testing, a $1.2 billion satellite designed to spot and track enemy missiles threatening the United States homeland, its deployed military forces abroad or allied nations will ascend to a surveillance post in space Thursday.

Rocket-builder United Launch Alliance unveiled a first-of-a-kind website Wednesday that shows potential customers exactly what it will cost to buy an Atlas 5 booster, along with expected savings based on the rocket’s demonstrated reliability, ULA’s on-time launch record and the company’s sophisticated guidance system.

SpaceX’s first launch since August took off Saturday from Vandenberg Air Force Base in California. A Falcon 9 rocket deployed the first 10 next-generation Iridium communications satellites, part of a $3 billion upgrade to the company’s space network. Liftoff occurred at 9:54 a.m. PST (12:54 p.m. EST; 1754 GMT), and the Falcon 9’s first stage landed on a barge in the Pacific a few minutes later.