Gallery: Antares rocket explodes

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.

Orbital Sciences Corp. announced Tuesday it selected United Launch Alliance’s Atlas 5 rocket to launch a Cygnus space station resupply mission in late 2015 while the company redesigns its Antares booster with a new engine following a catastrophic failure seconds after liftoff in October.

A commercial Northrop Grumman Cygnus supply ship berthed at the International Space Station fired its main engine for 50 seconds Tuesday in a test of the spacecraft’s ability to reboost, and possibly eventually deorbit, the massive research outpost.