CBS News reports that the scheduled May 7 launch of the Space Exploration Technologies Corp. (SpaceX) Dragon commercial cargo ship for a long-awaited demonstration flight to the international space station “almost certainly” will be delayed to May 10 and possibly beyond.

The report, citing “multiple NASA sources,” said a May 7 launch from Kennedy Space Center in Florida has been “ruled out” because SpaceX engineers need more time to complete preflight test and checkout, “although there was confusion in some quarters as to whether there might be a slim chance of keeping on schedule if additional analyses could be completed in time.” If the company is unable to launch on May 7 or the backup date of May 10, it will have to wait until at least May 19, CBS News said.

NASA had no official comment on the launch date because, one official said, the SpaceX flight is being billed as a commercial operation and “it’s up to SpaceX to make any announcements.”