SpaceX launched a secret mission for the U.S. Space Force today (Sept. 10) from California's central coast.

A Falcon 9 rocket lifted off from Vandenberg Space Force Base today at 11:42 a.m. EDT (1542 GMT; 8:42 a.m. local time), kicking off a mission called USSF-153.

The rocket's first stage came back to Earth about 8.5 minutes later, landing in the Pacific Ocean atop the SpaceX drone ship "Of Course I Still Love You." It was the 27th flight for this particular booster, which is designated B1801. The record for a SpaceX rocket is 37, set last month during a Starlink launch.

USSF-153 is a classified mission, so little is known about its payloads — what they are or where exactly they're headed.

We likely won't get clarity from the webcast, which is expected to end shortly after the Falcon 9's first stage comes back to Earth.

However, the location of that touchdown provides some potentially useful information about USSF-153, according to NextSpaceflight.com.

The mission might be carrying "a batch of classified LEO [low Earth orbit] satellites for a U.S. government entity based on SpaceX's Starshield satellite bus, based on locations of rocket stage drop zones being exact fits with previous Starlink Group 15 launches," the outlet wrote.

Starlink is SpaceX's constellation of LEO broadband satellites. "Starshield leverages SpaceX's Starlink technology and launch capability to support national security efforts," SpaceX wrote in a description of the Starshield program.

Today's launch will be the 104th Falcon 9 mission of 2026. Eighty of the rocket's flights this year have been dedicated to building out the Starlink megaconstellation, which currently consists of more than 11,000 active spacecraft.

USSF-153 will be the 27th flight for this particular Falcon 9's first stage. The record for a SpaceX booster is 37, set last month during a Starlink launch.