SpaceX can add another gold star to its report card after its Dragon cargo vessel successfully undocked from the International Space Station early Thursday, now ready for its return journey back to Earth after spending a week attached to the orbiting lab.

A multi-purpose NASA spacecraft originally designed as part of the cancelled Constellation program is currently undergoing rigorous testing in preparation for a scheduled 2014 test flight, the US space agency has announced.

The second SpaceX demonstration launch for NASA's Commercial Orbital Transportation Services (COTS) has been rescheduled for a liftoff on Monday, May 7.

The upcoming launch of a SpaceX spacecraft and rocket on a demonstration flight to the International Space Station is expected to cross a key milestone on the path to operational, commercial missions.