After a week of false starts, SpaceX will try again early Saturday to launch a batch of military satellites from California.

A Falcon 9 rocket is set to lift off from Vandenberg Space Force Base during a window from 12:29 to 12:51 a.m. PT Saturday, Oct. 10, KSBY News reported. That is 3:29 a.m. ET.

The rocket carries 21 satellites built by Northrop Grumman for the Space Development Agency, which is part of the U.S. Space Force. The mission is known as Tranche 1 Transport Layer A, and it is the fourth launch of production satellites for the agency's network.

The launch has slipped several times. On Monday, the countdown stopped in the final minute. "Falcon 9 had an auto abort just prior to T-0. Vehicle and payload are in good health," SpaceX said on X. The company then passed on a Tuesday chance and moved the date again. The Santa Ynez Valley News, citing Vandenberg, said the Monday and Tuesday scrubs were due to technical issues.

The satellites will join a network called the Proliferated Warfighter Space Architecture. It is a mesh of satellites in low orbit meant to send military data quickly around the world and help track missiles, Spaceflight Now reported. Three earlier launches have put 63 of these satellites in orbit. The first group of the network is expected to begin working for the Defense Department in 2027.

When it is finished, this first group will have 126 data satellites and 28 tracking satellites, Spaceflight Now reported.

About 7.5 minutes after liftoff, SpaceX plans to land the booster back at Vandenberg. People in Santa Barbara, San Luis Obispo and Ventura counties may hear one or more sonic booms. SpaceX will stream the launch on its website starting about 10 minutes before liftoff.

What we know: SpaceX is targeting 12:29 a.m. PT Saturday for the 21-satellite launch.
What we don't: Whether the rocket will finally fly on this try.