SpaceX's Starship, which is developing a spacecraft for Mars exploration, exploded during a ground engine ignition test. The company estimates that the cause is a structural defect in the nitrogen tank.

On the 18th, the Starship, which exploded during an engine ignition test on the launch pad in Texas, USA. /Courtesy of AP=Yonhap News

On the 19th (local time), SpaceX announced on its website that "initial analysis found a potential defect in the nitrogen gas pressure tank (COPV) mounted on the Starship nose cone," adding that "an analysis of the entire data is underway to determine the exact cause."

The incident occurred at 11 p.m. (Central Time) on the 18th at the Texas Starbase launch pad. During the pre-test process for the 10th test flight, the rocket was fixed while supercooled fuel was injected and six engines were sequentially ignited in a "static fire" test, when a sudden release of energy caused a gas explosion and a fire.

SpaceX explained that there were no casualties at the time of the accident and that there were no hazards to nearby areas. This incident was first reported to the public through a local county authority's announcement, and footage of the explosion with a huge column of fire rapidly spread online.

U.S. media reports indicate that this accident will inevitably delay the Starship development schedule. Previously, SpaceX had failed in all seven to nine Earth orbit test flights conducted in January, March, and May of this year, experiencing either explosions or disintegration.

As a result of this incident, SpaceX is expected to undergo further investigations by U.S. authorities.

Starship is a key project to realize CEO Elon Musk's vision of making humanity a "multiplanetary species" by migrating to Mars. The second stage spacecraft of Starship measures 52 meters in length and 9 meters in diameter, capable of transporting up to 100 passengers and 100 tons of cargo. When combined with the first-stage rocket "Super Heavy" (71 meters in length), the total height reaches 123 meters.