The first orbital launch attempt for SpaceX’s Starship and Super Heavy booster in April ended explosively about four minutes into its test flight, and the FAA isn’t ready to clear a follow-up attempt yet. Today, the agency closed its mishap investigation and said the report identified 63 actions that need to be implemented by SpaceX before launches can resume. They include redesigns to prevent leaks and fires, a redesigned launch pad, and other fixes.
A new post from SpaceX discussing “Upgrades ahead of Starships’s second flight test” appeared shortly afterward that didn’t directly reference the 63 actions, but its details on why the first test flight lost control reflect what the FAA says needs to be addressed.
Testing development flight hardware in a flight environment is what enables our teams to quickly learn and execute design changes and hardware upgrades to improve the probability of success in the future. We learned a tremendous amount about the vehicle and ground systems during… pic.twitter.com/kzMEBHwWyz
— SpaceX (@SpaceX) September 8, 2023
The SpaceX post confirms leaking propellant from the Super Heavy booster “eventually severed connection with the vehicle’s primary flight computer.” That was enough to cut off communications to most of the booster engines and send it flying out of control. Additionally, a destruct command issued automatically by the Autonomous Flight Safety System (AFSS) had an “unexpected delay” before detonators fired, and the Starship broke up 237 seconds after launch.”
The launch in April caused extensive damage to the pad and immediate surrounding areas, kicking up dirt and dust that rained down on towns miles away, problems that were predicted by some observers citing the lack of a trench or water system to divert the rocket’s flames. Last month, SpaceX posted a video of a static fire test with the flame deflector system now in place.
Bloomberg said that the US Fish and Wildlife Service found the first launch “left a 385-acre debris field that flung concrete chunks as far as 2,680 feet from the launchpad and sparked a 3.5-acre fire.” CNBC reported in the spring that a collection of environmental and cultural-heritage nonprofits filed a lawsuit against the FAA, saying that approving the test without a comprehensive environmental review violated the National Environment Policy Act.
According to the FAA, before launching again, the company will also need to get a license modification that “addresses all safety, environmental and other applicable regulatory requirements.”
SpaceX recently brought a new Starship prototype to the launch pad in Boca Chica, Texas, with Elon Musk saying on Tuesday that it was ready to launch “awaiting FAA license approval.” Upgrades mentioned to address problems from the first test include “leak mitigations and improved testing on both engine and booster hardware,” an expanded fire suppression system on the Super Heavy rocket, changes to the AFSS to make it more reliable, as well as “significant reinforcements to the pad foundation and the addition of a flame deflector.”
It also said it’s made other changes unrelated to the first test, with a new hot-stage separation system that uses the Starship’s second-stage engines to push away from the booster, as well as fully electronic thrust vector controls for the Raptor engines on the booster that it claims are more energy efficient and have fewer points of failure than traditional hydraulic systems.
The final report cites multiple root causes of the April 20, 2023, mishap and 63 corrective actions SpaceX must take to prevent mishap reoccurrence. 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 closure of the mishap investigation does not signal an immediate resumption of Starship launches at Boca Chica. 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.