Photos: Tuesday’s Atlas 5 rollout

United Launch Alliance’s Atlas 5 rocket made its way back to the pad at Space Launch Complex 41 at Cape Canaveral Space Force Station on Thursday morning for a mission carrying national security mission payloads, collectively codenamed Silentbarker. Liftoff has been rescheduled for at 8:47 a.m. EDT (1247 UTC).

Spare parts warehoused in the the United States and Russia will help Boeing finish assembly of a third space station docking port to receive arriving astronauts aboard Boeing’s CST-100 Starliner and SpaceX’s Crew Dragon capsules, replacing a unit lost in a Falcon 9 launch failure last year.

United Launch Alliance said Thursday it is targeting Sept. 26 for the next attempt to send a classified U.S. government spy satellite into orbit aboard a Delta 4-Heavy rocket, following an abort Aug. 29 just three seconds before liftoff from Cape Canaveral.