Northrop Grumman’s Cygnus cargo spacecraft, on a resupply mission to the International Space Station, has been delayed due to a main engine issue.

The NG-23 mission launched on Sept. 14 from Cape Canaveral aboard a SpaceX Falcon 9, carrying 11,000 pounds of scientific experiments and supplies for the seven astronauts aboard.

While the spacecraft reached a safe orbit and deployed its solar arrays, its main engine shut down early during two planned burns, forcing NASA and Northrop Grumman to reassess its arrival date, the USA Today has reported.

Once resolved, astronauts Jonny Kim and Zena Cardman will capture Cygnus with the station’s robotic arm and attach it to the Unity module.