Photos: Atlas 5 rocket aims for International Space Station

Astronauts Terry Virts and space station commander Barry “Butch” Wilmore ventured back outside Sunday for their third spacewalk in eight days to complete initial preparations for upcoming dockings by commercially developed Boeing and SpaceX crew ferry ships.

Carrying a Cygnus supply ship bound for the International Space Station, an Orbital ATK Antares rocket lifted off Monday from the Mid-Atlantic Regional Spaceport at Wallops Island, Virginia.

A commercial Cygnus supply ship left the International Space Station on Monday after delivering more than 5,000 pounds of cargo and experiments, ready to start a week of standalone operations to include a groundbreaking microgravity fire experiment and deployment of four commercial weather-monitoring CubeSats in orbit.