In March of this year, the aerospace company SpaceX conducted the eighth test launch of the Starship spacecraft with the super-heavy carrier rocket Super Heavy. Like the previous launch, it ended with the loss of the ship, which exploded a few minutes after the launch. Now SpaceX has reported what exactly caused the failure.
Image source: SpaceX
SpaceX said in a statement that one of the Raptor’s center engines experienced a “flare” followed by an “energetic event” that shut down the engine. Two other Raptor engines immediately shut down, as did one of the Raptor engines optimized for space, causing the rocket to enter an uncontrolled descent.
«The most likely root cause of the loss of Starship was determined to be a hardware failure in one of the upper stage’s Raptor core engines, which led to unintended fuel mixing and ignition,” SpaceX said in a statement.
The eighth Starship test flight is very similar to the seventh test flight. Both stages separated successfully, and both times the Super Heavy booster was successfully returned to Earth and picked up by the Mechazilla system. However, both missions were not entirely successful, as the Starship was lost. The ninth test launch of the Starship system is scheduled for May 27.
As for the Super Heavy booster, it landed successfully, but the process did not go smoothly. During the descent, only 11 of the 13 engines used for the initial boost fired successfully. As it approached the Mechazilla tower, 12 of the 13 engines fired. SpaceX has determined the reason why not all of the engines fired as expected. According to the company, this was due to overheating. To prevent this from happening again in the future, SpaceX engineers reinforced the problem areas with additional insulation.
The fixes for Starship consisted of tightening bolts on some critical components of the vehicle and optimizing the fuel system to prevent flammable gases from igniting when not needed. “Starship’s upper stage will receive additional preload on key components, a new nitrogen purge system, and improvements to the fuel system. Future versions of Starship will feature the Raptor 3 engine, which will receive additional improvements to improve fault tolerance,” SpaceX said in a statement.
It also said that the investigation involved more than 100 long-term tests of Raptor engines, which were monitored by the US Federal Aviation Administration (FAA) and the National Aeronautics and Space Administration (NASA). Earlier this week, the FAA issued a statement saying it was conducting a “comprehensive review” following the accident during Starship’s eighth test launch.
During SpaceX’s ninth test launch, the Super Heavy booster, which was used during the seventh launch, will be used for acceleration. The super heavy booster has never been used again before. The Starship launch window opens on May 27 at 19:30 local time (May 28, 02:30 Moscow time). A live broadcast of the launch will be available on the SpaceX website and on the company’s X social media account.