Live coverage: Atlas 5 countdown and launch journal

Air Force meteorologists are expecting good weather to launch the Delta 4 rocket with a military communications satellite when the sun goes down Friday evening at Cape Canaveral.

NASA has selected 14 companies for contracts of more than $370 million to advance technology for human missions to the moon and Mars. Most of the money will support flight demonstrations by SpaceX, United Launch Alliance, and other companies that could lead to in-space refueling and propellant depots for reusable lunar landers and deep space transportation vehicles.

The heavy-lift version of the United Launch Alliance’s new Vulcan rocket will sell for half the price of today’s Delta 4-Heavy and a third of the price tag for the previous Titan 4, while offering a substantial increase in performance for nation’s largest defense spacecraft.