Starship Booster Explodes Unexpectedly During SpaceX Ground Test

Footage of the explosion.
Gif: NASA Spaceflight/Gizmodo

SpaceX is in the midst of preparing its Starship rocket for its inaugural orbital launch, but an apparent explosion of the Super Heavy booster during tests at the company’s facility in Boca Chica, Texas, may represent a serious setback.

Update: July 12, 8:50 a.m. ET: New details are emerging about the anomaly. A “cloud of well-mixed methane and oxygen gas was accidentally ignited,” and it “functioned like a small fuel-air bomb,” resulting in in the explosion and shockwave, according to Teslarati.

In a tweet that has since been deleted, Elon Musk suggested the event was planned and that it was a part of “booster engine testing.” Musk later removed the tweet, saying the anomaly at the launch mount was “actually not good.” In a subsequent tweet, the SpaceX CEO said the anomaly “was specific to the engine spin start test,” as the 33 Raptor engines require a “complex start sequence.” Musk added that, going forward, “we won’t do a spin start test with all 33 engines at once.”

Overnight, Musk said the base of Booster 7 “seems ok by flashlight,” but SpaceX officials “shut down the pad for the night for safety.” Ground teams will “know more in the morning,” he added.

Original post follows.

The explosion happened around 5:20 p.m. ET, and it was as unexpected as it was severe. No word yet on the cause of the anomaly or whether anyone was hurt during the incident. The explosion was followed by a significant amount of fire in the vicinity of the giant booster rocket; flames and smoke could still be seen wafting from the launch pad an hour after the incident, but the situation at the test site didn’t appear to be worsening.

A static fire test was not expected today, and the launch pad had not been prepared or cleared for such a test (as far as we can tell). Venting from directly beneath the booster increased dramatically in the moments prior to the explosion, which produced a powerful fireball and shock wave. SpaceX did not immediately respond to our request for more information.

The Elon Musk-led company is currently testing Super Heavy Booster 7 at its Boca Chica facility, known as Starbase. The prototype booster, with its 33 Raptor engines, arrived at the launch mount in late June. A Starship second stage will eventually be stacked on top, forming a fully stacked Starship rocket. Musk was hoping for an orbital test flight of the system in July, but that seems unlikely given today’s events.

It’s likely that Booster 7 experienced some sort of damage during the explosion, whether it be to the dozens of Raptor engines or to the booster itself. Likely both. SpaceX will need to fix (or replace) the booster and determine the cause of the anomaly. It’s also not clear if the incident damaged the launch mount, which is equipped with a pair of mechanical arms known as “chopsticks,” which lift and hold the booster in place.

SpaceX is designed to transport cargo and passengers to orbit, the Moon, and Mars. The company is currently under contract with NASA to modify the system as a means for landing astronauts on the lunar surface. The Federal Aviation Administration (FAA) recently cleared SpaceX for site expansion, bringing Starship closer to its inaugural launch.

This is a developing story. Please check back for updates.