Liquid Oxygen (LOX) Tank On Booster 18 Ruptured While Testing

By Wes Oleszewski- ANN Spaceflight Analyst

SpaceX has suffered what could be a large set-back in its Starship Program. 

On November 21, the Liquid Oxygen (LOX) tank on Booster 18 ruptured while testing. This is the first of the Block 3 Starship booster stages, which are the third generation of the huge Starships that have recently launched. The failure took place at SpaceX’s Masseys test facility in Texas. As of this writing no injuries have been reported. Booster 18 was rolled out to Masseys on November 20 expecting to run through an early series of cryogenic tests in preparation for a flight sometime in early 2026.

Damage to the booster involves a massive rip and deforming of the stage’s midsection. When the burst happened, it was captured by Nasaspaceflight.com’s privately maintained remote cameras. A large area of escaping cryogenic gas erupts near the booster’s boat-tail at about 05:39 Central Time. This is the area just above where the heavily constructed engine mountings are located. Later images show a large deformation and gash. During this specific test only liquid oxygen and nitrogen were used, thus there was no methane hazard.

Just the size of the booster alone, however, represents a hazard. Since the load bearing structure has been highly compromised and there is no service structure the stabilize the towering remains of the damaged rocket, SpaceX will have to quickly come up with a plan to stabilize and then remove the wreck. With SpaceX’s other test site being rebuilt after the June 18, 2025 Space Ship 36 explosion, during a six-engine static fire attempt, SpaceX now has nowhere to cryo-test Starship booster stages. This lack of facilities alone can represent a greater delay hazard than the loss of Booster 18 itself.

Currently, stacking of Booster 19 has reportedly not yet begun. The combination of these factors will likely add up to a frustrating delay in the overall Starship program which has yet to as much as place any piece of hardware into a sustained orbit of the Earth. Most of SpaceX’s Starship goals for 2026 will now likely be set-back to assorted degrees.

Although private SpaceX “watchers” have come up with a slew of probable causes for this accident, we here at ANN will not participate in any such speculation at this very early date.

FMI: www.spacex.com