Live coverage: Dragon supply ship back on Earth

Juggling simultaneous launch campaigns on both coasts, a team of SpaceX engineers put a Falcon 9 rocket through a customary countdown rehearsal and hold-down firing Tuesday at Vandenberg Air Force Base in California ahead of a scheduled liftoff Sunday.

Astronaut Christina Koch, launched to the International Space Station in March, marks her 289th day in space Saturday, breaking retired astronaut Peggy Whitson’s world record for the longest single spaceflight by a female.

A Northrop Grumman Antares rocket stands on pad 0A at Wallops Island, Virginia, on a frigid morning hours before a planned liftoff with more than 8,000 pounds of cargo heading for the International Space Station.