A Falcon 9 rocket launch from Vandenberg Space Force Base won’t occur before Sunday morning.

Space Exploration Technologies, which manufactures Falcon rockets, said the team will now target 8:18 a.m. Sunday for the liftoff from Space Launch Complex-4 on South Base.

The announcement made Wednesday afternoon followed another one hours earlier saying the launch had slipped to at least Saturday. 

SpaceX officials explained the plans for a Sunday morning launch as being “for constellation optimization.”

Launch times are decided by where the rocket’s cargo need to be placed in space.

After doing its job, the rocket’s first-stage booster will land on a drone ship positioned in the Pacific Ocean several hundred miles south of the Central Coast.

Plans to launch Monday were foiled by unfavorable weather, and crews called off Tuesday’s countdown to provide the team time to review second-stage data, SpaceX said.

The delay until Saturday was attributed to a need for additional pre-launch checkouts.

The Falcon rocket, in line for the first launch of 2023 from Vandenberg, will deliver 51 Starlink satellites into space. 

A live webcast of the mission will be available starting five minutes before liftoff at the SpaceX website.