SpaceX launched its second classified mission for the U.S. Space Force in less than a week tonight (Sept. 16).

A Falcon 9 rocket lifted off from California's Vandenberg Space Force Base today at 9:07 p.m. EDT (6:07 p.m. local California time; 0107 GMT on Sept. 17).

We don't know much about tonight's mission, which was called USSF-259. And we didn't learn much from SpaceX's webcast, which ended shortly after the Falcon 9's first stage returned to Earth for a landing in the Pacific Ocean atop a drone ship about 8.5 minutes after launch.

That touchdown was the 13th for this particular booster, which is designated 1097. One of the booster's previous landings was a big milestone for SpaceX. This past April, B1097 pulled off SpaceX's 600th touchdown of an orbital-class rocket, during a launch that sent 25 of the company's Starlink internet satellites to low Earth orbit.

Tonight's mission was the second that SpaceX has flown for the U.S. Space Force in a six-day span: A Falcon 9 launched the similarly classified USSF-153 from Vandenberg on Sept. 10.

Tonight's launch was SpaceX's 110th of 2026. The vast majority of the company's flights so far this year — 106 of them, in fact — have been performed by the workhorse Falcon 9.

The powerful Falcon Heavy has launched twice in 2026, as has SpaceX's next-gen megarocket, Starship. Both Starship liftoffs this year have been suborbital test flights. The next Starship launch, which is expected to occur in the next two weeks, will apparently take the vehicle orbital for the first time.

Editor's note: This story was updated at 11:50 p.m. ET on Sept. 15 with the new launch date of Sept. 16. It was updated agai at 9:28 p.m. ET on Sept. 16 with news of successful launch and rocket landing.