"Due to a variety of interrelated factors, including the company's continuing processing, inspection and testing of the flight vehicle at Wallops Island, and NASA's scheduling of crew activities on the International Space Station in preparation for upcoming cargo and crew launches, Orbital ATK is currently working with NASA to target a window in the second half of September for the launch of the OA-5 [Antares] mission," the statement reads.
According to the statement, the exact launch date will be identified in the coming weeks.
Two launches of the Antares rocket have been successful, while the has been a disaster. In October 2014, the rocket exploded seconds into its launch at the Wallops Flight Facility located on the Atlantic coast of the US state of Virginia.