Live coverage: Atlas 5 countdown and launch journal

With Hurricane Isaias threatening Florida’s East Coast, astronauts Doug Hurley and Bob Behnken are awaiting a go-ahead on plans to undock from the International Space Station Saturday, setting up a fiery plunge to splashdown Sunday, presumably in the Gulf of Mexico, to close out a 64-day flight.

A United Launch Alliance Delta 4 rocket went through a practice countdown and fueling exercise today to prepare for its Dec. 7 liftoff to deliver a U.S. military communications satellite into space.

United Launch Alliance and SpaceX recently won contracts worth $739 million to send six missions into orbit for the U.S. military, and the Air Force has announced a new title for its flagship launcher program, dropping “expendable” from the name in a new era of reusable rockets.