SpaceX is preparing to launch a Falcon 9 rocket with an undisclosed number of satellites on behalf of the National Reconnaissance Office (NRO). The spacecraft, which are believed to be Starshield satellites, make up the third batch of what the NRO calls its "proliferated architecture."

Liftoff of the NROL-113 mission from Vandenberg Space Force Base is set for 8:20 p.m. PDT (11:20 p.m. EDT, 0320 UTC). Spaceflight Now will have live coverage beginning about 30 minutes prior to launch.

The Falcon 9 booster supporting this mission, tail number B1063, will be launching for a 20th time. It previously supported the launches of NASA's Double Asteroid Redirection Test (DART), the Transporter-7 rideshare mission and 14 Starlink satellite missions.

The mission marks the most seasoned booster to launch a national security mission on behalf of the NRO. The previous record was the NROL-146 mission, another Starshield launch, which liftoff off on B1071's 16th flight.

About 8.5 minutes after liftoff, B1063 is set to land on the SpaceX droneship, 'Of Course I Still Love You.' If successful, this will be the 100th landing on this droneship and the 345th booster landing to date.

"This is NRO's third proliferated architecture launch within four months, demonstrating the rapid pace of delivery for these systems," the NRO wrote in a Sept. 4 social media post.

The NRO plans to launch about six missions for this proliferated constellation in 2024. Its most recent launch came on June 29, 2024.