The Federal Aviation Administration has concluded its review of SpaceX’s investigation of the second Starship launch in November, with the regulator saying Monday that it accepted the “root causes and 17 corrective actions” identified by the company.
While this means the investigation is now closed, SpaceX must implement all the corrective actions and apply for a modified launch license before it can fly Starship again. According to the FAA’s statement on Monday, they are currently evaluating SpaceX’s license modification request and awaiting additional information before making a final determination.
SpaceX’s second orbital flight test of the nearly 400-foot-tall Starship rocket in November marked a significant milestone for the company. All 33 of the Raptor engines on the Super Heavy booster successfully powered on, and the rocket managed to execute a difficult “hot-stage separation” for the first time, with the upper stage pushing away from the booster. However, like the first test in April, this one also ended in a fiery explosion.
Whenever a rocket launch experiences catastrophic issues during flight, the FAA opens a “mishap investigation,” which is what occurred here. These investigations are led by the company and reviewed by regulators, who must approve the analysis and ensure that corrective actions are implemented. After the first test, the FAA required SpaceX to complete 63 corrective actions.
According to the FAA, SpaceX ultimately identified seven changes to the booster and ten to the Starship vehicle as part of their corrective actions. These included redesigning vehicle hardware, updating control systems, and conducting new analyses based on data from the second test flight.
- Seven booster corrective actions were identified, including:
- Redesigns of vehicle hardware to increase tank filtration and reduce slosh
- Updated thrust vector control system modelling
- Reevaluation of engine analyses based on OFT-2 data
- Updated engine control algorithms
- Ten Starship corrective actions were identified, including:
- Hardware redesigns to increase robustness and reduce complexity
- Hardware changes to reduce leaks
- Operational changes eliminating pre-second engine cutoff propellant dumps
- Flammability analysis updates
- Installation of additional fire protection
- Creation of analytical guidance
- Performance of transient load analysis
- Modeling updates
In a rare post-launch postmortem, SpaceX shed light on some of these corrective actions in an update published on Monday. The company stated that the likely cause of the “rapid unscheduled disassembly” (aerospace lingo for explosion) of the booster was a filter blockage in one of the Raptor engines, which failed energetically and led to the total loss of the booster.
The Starship upper stage met its end when a propellant leak started a fire and severed communication between the spacecraft’s computers, causing an engine shutdown. This triggered the autonomous flight termination system to destroy the vehicle around seven minutes into the flight.
In the update, SpaceX also mentioned that some of the hardware changes and design upgrades have already been implemented on the versions of the Starship that will fly for the third orbital flight test. Elon Musk, CEO of SpaceX, stated on his social media platform, X, that this mission could potentially take place in the second week of March.
“More Starships are ready to fly, putting flight hardware in a flight environment to learn as quickly as possible. Recursive improvement is essential as we work to build a fully reusable launch system capable of carrying satellites, payloads, crew, and cargo to a variety of orbits and Earth, lunar, or Martian landing sites,” SpaceX said in the update.
Ultimately, SpaceX’s goal is to complete the full mission profile, which includes the Super Heavy booster completing a “boost back burn” and performing a controlled splashdown in the Gulf of Mexico. The Starship would then fly halfway around the world and land in the Pacific Ocean.
