NASA Ready to Try Again With Commercial Resupply Missions to International Space Station

Orbital ATK had been sidelined following Antares explosion last year.

If everything goes according to plan, the launch will be Orbital ATK’s fourth commercial resupply flight to the International Space Station and its first since a little over a year ago when an explosion shortly after launch destroyed the Antares rocket, Cygnus vessel and thousands of pounds of cargo.

An independent investigation completed by NASA around the anniversary of the Antares explosion found the cause was likely an explosion in a turbo-pump located in one of the rocket's two engines.

For the Dec. 3 launch, Orbital ATK said it plans to use a different rocket -- the workhorse Atlas V -- which has been used to put many satellites into orbit but has never been used to send a cargo to the space station.

Also new is the upgraded Cygnus, which can carry 7,000 pounds of cargo -- 25 percent more than its predecessor -- making the vehicle even more appealing to NASA, which relies on its resupply missions to stock the space station with food, clothes and science experiments.

When Cygnus reaches the space station, it will be pulled in by the station's robotic arm and docked for unloading. Cygnus will also help take out the trash -- astronauts will fill up the spacecraft with unneeded items before releasing it to burn up in Earth's atmosphere.