The countdown froze at T-40 seconds. Then it restarted. Then it stopped again. A hydraulic pin holding the launch tower arm in place failed to retract, forcing SpaceX engineers into a last-minute scramble as millions watched the debut launch of Starship V3 slip away seconds before liftoff.

SpaceX had fueled the massive rocket and cleared the pad for launch. But a problem involving ground support systems, including the water diverter beneath the launch mount, forced the company into a hold. Minutes later, SpaceX officially scrubbed the mission, delaying the first flight of its upgraded Starship V3 vehicle.

“New rocket, new pad, we’re learning a lot about these new systems,” SpaceX commentator Dan Huot said during the livestream. He added that the company expected another launch attempt as soon as Friday.

Final-second launch hold

The mission marked the planned 12th test flight of Starship and the first demonstration of the V3 configuration. Before the scrub, SpaceX loaded propellant and prepared the vehicle for launch from its Texas test site.

The countdown entered its final minute before the automated system halted the sequence. Huot later explained that the water diverter beneath the launch system triggered the hold.

He said teams needed time to review the data and decide whether troubleshooting was necessary. SpaceX can remain in a hold for several minutes during terminal countdown operations.

If SpaceX launches Friday, the company plans to use the same 90-minute launch window. Liftoff would target 6:30 p.m. EDT.

Bigger and stronger rocket

Fully stacked with the Super Heavy booster, Starship V3 stands 408 feet tall. It remains the tallest and most powerful rocket ever built.

SpaceX introduced several major upgrades with the new version. The rocket uses the latest V3 Raptor engines, with 33 engines powering Super Heavy and six engines installed on Ship.

The new engines deliver greater thrust while simplifying the overall system design. Engineers also reduced the number of grid fins on the booster from four to three.

The company redesigned the hot-stage ring as well. Earlier versions discarded the structure during flight. The new version keeps it attached to the booster for reuse after separation.

SpaceX uses hot-stage separation during flight. That process allows Ship to ignite its engines before fully detaching from the booster.

Critical Starship milestone

Unlike some earlier flights, Flight 12 would not attempt to recover either the booster or the Ship vehicle. Instead, SpaceX wants to focus on testing the upgraded rocket’s ascent and reentry performance.

The mission profile calls for Starship to separate from Super Heavy before continuing on a suborbital path. The spacecraft would then deploy 20 dummy Starlink satellites.

SpaceX also planned to release two operational satellites designed to photograph Starship’s heat shield during flight and transmit images back to Earth.

After reentry, Starship would perform several maneuvers, including a controlled flip, before splashing down in the Indian Ocean. The Super Heavy booster would fall into the Gulf of Mexico.

The test carries major significance for SpaceX. Recent filings tied to the company’s expected initial public offering showed it spent roughly $3 billion developing Starship over the past year. Total Starship spending has reportedly reached $15 billion.

NASA also depends heavily on Starship for its Artemis moon program. SpaceX plans to use a modified version of the spacecraft to land astronauts on the moon later this decade.

The company eventually wants Starship to launch large-scale cargo missions, including future satellite networks tied to artificial intelligence infrastructure.