SpaceX is preparing to launch a national security mission on behalf of the United States’ National Reconnaissance Office (NRO) from Vandenberg Space Force Base. The spy agency described the classified mission as “the second launch of NRO’s proliferated architecture, delivering critical space-based ISR (intelligence, surveillance and reconnaissance) to the nation.

The Falcon 9 rocket supporting this mission will lift off from Space Launch Complex 4 East (SLC-4E) at the opening of a two-hour window, set for 8:14 p.m. PDT (11:14 p.m. EDT, 0314 UTC).

Spaceflight Now will have live coverage beginning about 30 minutes prior to liftoff.

The Falcon 9 first stage booster supporting this mission, tail number B1081 in the SpaceX fleet, will be launching for an eighth time. Its previous missions included the launches of the Crew-7 astronaut mission to the International Space Station, two climate monitoring satellites (NASA’s PACE and the European Space Agency’s EarthCARE) and two Starlink flights.

A little more than eight minutes after liftoff, B1081 will land on the droneship, ‘Of Course I Still Love You.’ This will be the 95th booster landing for OCISLY and the 326th booster landing to date.

Proliferated architecture grows

This mission is the second launch of the NRO’s so-called “proliferated architecture,” following the launch of the NROL-146 mission in May. Reporting from Reuters earlier this year suggested that these satellites are based on the SpaceX-built Starshield satellite bus in partnership with Northrop Grumman.

In a statement to Spaceflight Now, the NRO said:

“NRO systems are designed, built and operated by the NRO. As a matter of national security we do not discuss the companies associated with the building of our systems, our contractual relationships with them, their specific activities, or the locations where NRO systems are built.”