The Antares rocket launch from the Wallops Island Flight facility was postponed yesterday for at least a week.
The reason: An Aerojet Rocketdyne engine for future use failed in testing.
The Orbital Sciences Corporation said that next launch window will be no earlier than June 17th.
It would be the second launch of eight planned commercial cargo flights to the International Space Station.
In the days ahead scientists will be looking at what caused the test failure of the rocket engine.