SpaceX will launch a series of military satellites this Friday (September 1) after a one-day delay, and you can watch it live. The Falcon 9 rocket, carrying 13 spacecraft from the US Space Development Agency (SDA), is scheduled to take off from Vandenberg Space Force Base in California on Friday. 10:26 PM ET (14:26 GMT; 7:26 AM California local time).

When the time comes, you’ll be able to watch it live on Space.com or directly via the company, courtesy of SpaceX. The broadcast is expected to start 15 minutes before kickoff. SpaceX initially attempted to launch the Tranche 0 mission on August 31, but delayed it for an unknown reason.

Friday’s launch will be SpaceX’s second support for the Proliferate Warfighter Space Architecture (PWSA), “a new multi-layered network of low-Earth orbiting satellites and support elements that will provide global military communications and missile warning, indication and tracking capabilities.” Wrote SpaceX. in the mission statement. PWSA’s first mission took place in early April, when Falcon 9 took off 10 satellites from Vandenberg.

According to SpaceNews, these first two missions are devoted to the creation of “Tranche 0,” a demonstration group of 28 satellites. Most are for communication purposes but some are designed to detect missiles.

Air and Space Forces magazine wrote in late March: “According to the plan, the Space Force will have hundreds of small satellites, and new ones will be launched every few years to improve stability and capabilities in orbit.”

If all goes as planned, Falcon 9’s first stage will land in Vandenberg approximately 7.5 minutes after launch today. According to SpaceX’s mission statement, this will be the 14th launch and landing of the launch vehicle. It is unclear when the satellites will be deployed; SpaceX has not released any information regarding this milestone. This is not surprising; Details are often lacking in national security missions.