FAA closes SpaceX Starship investigation, orders fixes
It’s been more than four months since the first integrated flight test of SpaceX’s Starship Super Heavy rocket, which resulted in the vehicle breaking apart several minutes into flight.
In a Sept. 8 update, the Federal Aviation Administration said it has closed the mishap investigation into the April 20 Starship flight, citing 63 corrective actions for SpaceX to take before the company can continue flying its gargantuan rocket at Boca Chica, Texas.
“Corrective actions include redesigns of vehicle hardware to prevent leaks and fires, redesign of the launch pad to increase its robustness, incorporation of additional reviews in the design process, additional analysis and testing of safety critical systems and components including the Autonomous Flight Safety System, and the application of additional change control practices,” the FAA’s update reads.
SpaceX’s Starship launched at 8:33 a.m. CDT (13:33 UTC) April 20 from the company’s orbital launch pad at its Starbase facility in South Texas. According to the company, the vehicle climbed to a maximum altitude of about 24 miles (39 kilometers) over the Gulf of Mexico.
“During ascent, the vehicle sustained fires from leaking propellant in the aft end of the Super Heavy booster, which eventually severed connection with the vehicle’s primary flight computer,” reads a Sept. 8 update on SpaceX’s website. “This led to a loss of communications to the majority of booster engines and, ultimately, control of the vehicle.”
The company said it has since implemented leak mitigations and improved testing for both engine and booster hardware, as well as “significantly expanded Super Heavy’s pre-existing fire suppression system” to mitigate future engine bay fires.
After the vehicle lost control during ascent and deviated from its expected trajectory, the Autonomous Flight Safety System, automatically issued the self-destruct command. However, there was a noticeable delay from the activation of the charges and the final breakup of the vehicle, which occurred 237 seconds after liftoff.
Neither SpaceX nor the FAA said why the Autonomous Flight Safety System experienced an “unexpected delay” following its activation, but the company said it is working to enhance and requalify the system to improve reliability. This is presumably one of the 63 corrective actions the FAA has tasked SpaceX with carrying out, but no extensive list has been made public as of Sept. 11.
In SpaceX’s Sept. 8 update, the company noted it was already working on several corrective actions. Perhaps most visibly has been the addition of a sound suppression system underneath the orbital launch mount. During the April 20 flight, the thrust from the Super Heavy booster caused the “structural failure of the launch pad deck foundation,” sending debris and sand into the air, according to the FAA.
SpaceX also said it was implementing several changes to Starship not related to the April 20 mishap. This includes the addition of a “hot-stage separation system,” which would see the upper stage “Ship” ignite three of its engines to push itself away from the Super Heavy booster.
The original plan was to induce a slight spin of the entire stack to separate the Ship before it ignited the engines. The April 20 flight did not reach this milestone.
SpaceX said it has also created a new electronic Thrust Vector Control system for the Super Heavy Raptor engines.
“Using fully electric motors, the new system has fewer potential points of failure and is significantly more energy efficient than traditional hydraulic systems,” SpaceX’s update reads.
Earlier this month SpaceX stacked its next Starship and Super Heavy vehicles at the launch pad for tests and an eventual flight. However, the FAA said that while the mishap investigation is closed, this does not signal a resumption of Starship launches.
“SpaceX must implement all corrective actions that impact public safety and apply for and receive a license modification from the FAA that addresses all safety, environmental and other applicable regulatory requirements prior to the next Starship launch,” the FAA said.
Video courtesy of SpaceX
Derek Richardson has a degree in mass media, with an emphasis in contemporary journalism, from Washburn University in Topeka, Kansas. While at Washburn, he was the managing editor of the student run newspaper, the Washburn Review. He also has a website about human spaceflight called Orbital Velocity. You can find him on twitter @TheSpaceWriter.