SpaceX faces setback as Booster 18 rupture halts Starship program progress

SpaceX’s recent attempt to advance its Starship program encountered a significant setback when Booster 18 experienced a rupture during a gas system pressure test. The incident occurred at the company’s Masseys site on November 21, 2025, just one day after the booster was rolled out for testing.

During the early morning testing, the Liquid Oxygen (LOX) tank on Booster 18 sustained damage that created a large hole. This anomaly is believed to have been triggered by the failure of a Composite Overwrapped Pressure Vessel (COPV) at the bottom of one of the booster’s larger sections, leading to a series of reactions that ultimately resulted in the rupture of the LOX tank. Notably, no propellant was onboard and the engines had not yet been installed at the time of the testing.

Photographic evidence from the scene reveals significant damage, but remarkably, the booster did not topple over immediately after the failure. Currently, the vehicle is being supported by a new Liquid Methane (LCH4) transfer tube, and it remains unclear how SpaceX plans to manage the situation safely, whether through stabilizing the booster with equipment or dismantling it for cleanup.

This incident echoes a similar mishap that took place five months prior when SpaceX lost Ship 36 due to a COPV explosion during a static fire. Investigations into the cause of Booster 18’s rupture are underway, although speculation exists that it could be related to welding failures or defects in the tank wall.

The implications for SpaceX’s operations are substantial. As it stands, the company currently has no operational flight boosters available, necessitating a shift in focus to Booster 19, which hasn’t yet begun stacking in Mega Bay 1. If construction on the new booster commences immediately, it would not be ready for cryogenic proof testing until late January 2026, delaying plans for the next phase of testing.

While Booster 19 has yet to be constructed, Ship 39, which is being readied in Mega Bay 2, is intended to accompany future tests. Still, its preparations have slowed due to the ongoing use of the Ship Cryo Thrust Stand for another project.

As a result of the Booster 18 incident, SpaceX faces an additional challenge: without a functioning booster, the testing of the new Pad 2 becomes complicated. The tank farm equipment on the pad requires verification and testing using an actual vehicle. The company could explore alternate options, such as modifying existing test tanks to facilitate preliminary tests or salvaging parts of Booster 18.

The failure comes in the wake of recent flight successes for the Starship program, which had been seeking momentum following challenges with earlier models. The timeline for Flight 12 now remains uncertain as SpaceX works to determine the cause of the anomaly and assembles a replacement booster.