SpaceX Starship explosion likely caused by propellant leak, Elon Musk says

On January 18, 2025By Littum

The explosion that destroyed the upper stage of SpaceX’s Starship vehicle yesterday (January 16) was likely caused by a leak, Elon Musk said.

Starship was launched yesterday afternoon from SpaceX’s Starbase site in South Texas, starting the seventh flight test of the 403-foot-tall (123-meter) megarocket.

Things went well at first. The vehicle’s two stages—the Super Heavy booster and the Ship upper stage spacecraft—separated in time, and the Super Heavy returned to Starbase as planned, where it was captured by the launch tower’s “chopstick” arms.

However, the ship ran into trouble shortly after the partner’s big moment. The 171-foot-tall (52 m) spacecraft broke apart over the Atlantic Ocean about 8.5 minutes after liftoff, creating a sky show seen by observers in the Turks and Caicos Islands and other nearby locations.

Although it’s still early in the anomaly investigation, SpaceX has already identified a likely cause, according to Musk, the company’s founder and CEO.

“Preliminary indication is that we had an oxygen/fuel leak in the cavity above the marine engine firewall, which was large enough to build pressure beyond the venting capacity. In addition to double-checking for leaks, of course, we will add fire suppression to that. volume and probably increase the vent area. Nothing so far to push the next launch past next month.” Musk said via Xthe social media platform he owns, about 2.5 hours after Flight 7 launched. (The Starship’s Raptor engines are powered by liquid oxygen and liquid methane.)

As the last part of that post indicates, SpaceX plans to fly Starship frequently in 2025; the company has applied for permission to launch the mega rocket from Starbase up to 25 times this year.

Related: SpaceX captures Super Heavy booster on Starship Flight 7 test, but loses upper stage (video, photos)

Starship Flight 7 breaks up and re-enters over Turks and Caicos pic.twitter.com/iuQ0YAy17O16 January 2025

This pressure overload apparently led to a fire “in the aft section of the ship, leading to a rapid unplanned disassembly,” SpaceX wrote in a blog post about Flight 7 last night and emphasized that this interpretation is based on preliminary data analyses. (“Rapid unplanned disassembly” is a term of art for a spacecraft explosion.)

“We will conduct a thorough investigation, in coordination with the FAA, and implement corrective actions to make improvements on future Starship flight tests,” the company added, citing the US Federal Aviation Administration.

“Starship flew within its designated launch corridor – as all US launches do to protect the public both on the ground, on the water and in the air,” SpaceX continued in the blog post. “Any surviving pieces of debris would have fallen into the designated hazard area.”

Still, the anomaly had some effects beyond the SpaceX sphere. “The FAA briefly slowed and diverted the aircraft around the area where spacecraft debris fell,” agency officials told Space.com via email yesterday afternoon, noting that normal flight operations resumed shortly thereafter.