The engines powering a SpaceX Falcon 9 rocket's first stage, a well-traveled booster attempting a record fifth flight in a mission to launch 60 Starlink internet satellites, roared to life and then immediately shut down Sunday in a dramatic-but-safe last-second launch abort.
SpaceX said on Twitter that the launch was scrubbed for the day, blaming the delay on a "standard auto-abort" after finding "out of family" data during a last-second engine power check. The company said it would announce a new launch date after conferring with the Air Force, which supports all launches from Florida's Space Coast.
While dramatic, the Falcon 9 is designed to safely shut down before liftoff if any critical systems malfunction. Similar aborts occurred in at least four previous launch campaigns and in one case, SpaceX was able to recover and launch later the same day. But Sunday's flight had to launch on time because of the weight of the rocket's 60-satellite payload and the demands of the planned orbit.
SpaceX test-fired the rocket's nine first stage Merlin engines Friday in an exercise the California rocket builder carries out before every Falcon 9 launch to make sure the rocket's propulsion system, flight computers and other critical components are operating normally. There were no problems with the "hot fire" test, clearing the way for Sunday's launch attempt.
The countdown appeared to go smoothly until engine startup at 9:22 a.m. EDT. A SpaceX commentator called out the final moments of the countdown, saying "...three, two, one, zero, ignition, liftoff" as billowing clouds of exhaust shot away from the base of the rocket. But the booster did not visibly move and the commentator quickly said "disregard. We have an abort."
A few moments later, an engineer on the countdown audio loop said "launch abort on engine high power" as white exhaust vapor rolled back over launch pad 39A, briefly obscuring the rocket from view.
The goal of the mission, whenever it takes off, is to deploy a sixth batch of 60 Starlink internet relay satellites. Three hundred Starlinks were launched during five previous missions as the company ramps up to begin limited commercial service across the northern U.S. and Canada later this year.
SpaceX has regulatory approval to launch some 12,000 Starlink satellites to provide uninterrupted, global broadband service.