The Falcon 9 rocket returned to flight and delivered 25 Starlink satellites into orbit Saturday afternoon, days after a different mission at Vandenberg Space Force Base involved a glitch that prompted a brief investigation.

The SpaceX rocket blasted off at 12:58 p.m. from Space Launch Complex-4 on South Base. Minutes later, the first-stage booster successfully landed on the droneship in the Pacific Ocean.

An hour after liftoff, SpaceX confirmed the 25 Starlink satellites had deployed.

Vandenberg’s week started with another Falcon rocket launch that initially appeared a complete success since SpaceX confirmed the batch of 25 Starlink satellites on board had separated from the rocket. 

But hours after Monday morning’s liftoff, SpaceX confirmed a glitch that prompted a mishap investigation monitored by the Federal Aviation Administration.

Friday afternoon, FAA officials confirmed the agency had cleared Falcon flights to resume.

On Saturday, SpaceX blamed the glitch on efforts to ensure the rockets’ used second stages don’t remain in orbit to become space debris.

During the flight, the second stage experienced “an off-nominal condition caused by a failed ignition due to a gas bubble in the transfer tube ahead of the planned deorbit burn,” according to SpaceX. Igniting the motor is a key step to prep for removing the component from space. 

Despite the glitch, the vehicle then performed as designed to successfully passivate the stage, or remove remaining fuel, gases and more. 

The stage reentered Earth’s atmosphere approximately 10.5 hours over the Southern Indian Ocean, SpaceX said. No reports have been received of debris sightings or third-party damage.

The incident occurred as SpaceX teams have conducted testing to refine the pre-burn engine procedures. 

“The goal of this testing is to ultimately ensure space safety, effectively ensuring that all Falcon second stages completely deorbit, leaving behind no space debris,” SpaceX said. 

In 2024, 13 out of 134 upper Falcon 9 stages remained on-orbit after successful payload separation, SpaceX said. 

Last year SpaceX reduced this number to three out of a total of 165 launches from Vandenberg and Florida.

All 16 of those second stages completed the passivation measures, with six since reentering.

Mission profiles called for the other 10 to remain in orbit, where they are continuously tracked so that satellites with maneuvering capabilities can make adjustments if needed. 

SpaceX said the deorbit reduction effort “requires novel methods” in order to perform deorbit burns on some missions. 

“These tests provide critical data and insights, continuously improving the reliability of Falcon and protecting public safety across all missions,” SpaceX added. 

The investigation prompted SpaceX to briefly pause launches with Saturday missions delayed just a day. 

SpaceX plans another Starlink mission from Vandenberg as soon as Wednesday. That liftoff is planned between 6:07 and 10:07 a.m. with the first-stage booster then landing on the droneship in the Pacific Ocean.