A United Launch Alliance Delta 4-Heavy rocket lifted off from Vandenberg Air Force Base in California at 1:47 p.m. PDT (4:47 p.m. EDT; 2047 GMT) Monday with a classified satellite for the National Reconnaissance Office, the U.S. government’s spy satellite agency.

The capture came after Northrop Grumman engineers adjusted the sensitivity of main engine fault detection software that prematurely triggered shut downs during two rendezvous thruster firings Tuesday.

SpaceX launched the vehicle on a Falcon 9 rocket from Cape Canaveral Space Force Station on Sunday, Sept. 14, at 6:11 p.m. EDT (2211 UTC). It’s scheduled to be berthed to the ISS by NASA astronaut Jonny Kim on Wednesday, Sept. 17.