While SpaceX gears up for the highly anticipated ninth test of its Starship launch vehicle, the company, being open as always, has disclosed why Flight 8’s upper stage failed, which subsequently resulted in it blowing up in midair back on March 6. The test flight, which took off from the company’s Starbase site in Texas, came to a screeching halt within minutes of reaching the sky when the top stage — known as Ship — experienced a catastrophic engine failure. Although the Super Heavy booster returned safely to Starbase with the aid of “Mechazilla”, the upper-stage anomaly cut the mission short, halting its attempt to deploy simulated Starlink satellites.

SpaceX Reveals Engine Flash Caused Starship Flight 8 Explosion, Flight 9 Cleared for May 27 Launch

As per a SpaceX update released on May 22, the mishap was caused by a hardware failure in one of the ship’s centre Raptor engines. The failure resulted in a “flash” near the sea-level Raptor, which triggered a shutdown of multiple engines, including vacuum Raptors, and initiated vehicle tumbling. Two minutes later, communications were lost and the automated flight termination software activated, leading to the vehicle’s destruction. The incident closely mirrored that of Flight 7, which also ended in an upper-stage explosion, albeit from a fire in a different engine section.

The flash was traced to inadvertent propellant mixing and ignition within the engine bay. SpaceX mentioned further inspection revealed overheating in the ignition system of several engines. While Super Heavy returned to Earth mostly intact, ignition issues affected 2 of its 13 engines during the boostback burn. SpaceX is reinforcing engine insulation and modifying thermal systems to prevent recurrence in future flights.

To correct the faults, SpaceX engineers implemented structural and mechanical improvements. More than 100 long-duration test firings at McGregor, Texas, overseen by the FAA, NASA, and Space Force, involved tighter joints, a new nitrogen purge system, improved propellant drainage, and Raptor 3 engine preparations.

With the FAA now satisfied SpaceX has resolved the issues, Starship is cleared to return to flight. Flight 9 is scheduled to launch no earlier than May 27 aboard a reused Super Heavy booster. SpaceX will livestream the launch on its official platforms starting at 7:30 p.m. EDT.