Hier ist schön beschrieben, was Orbital Sciences (Antares/Cygnus) von +SpaceX (Falcon 9/Dragon) unterscheidet.

Orbital Sciences Scrubs Launch After Premature Cord Detachment | Autopia | Wired.com

Veteran space launch company Orbital Sciences is scheduled to make its first demonstration test flight later today of its new Antares rocket as part of NASA’s commercial orbital transportation system …