TL;DR Flight Test 1:
- 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. This led to a loss of communications to the majority of booster engines and, ultimately, control of the vehicle.
- unexpected delay following AFSS activation
Changes:
- implemented leak mitigations and improved testing on both engine and booster hardware ... expanded Super Heavy’s pre-existing fire suppression system in order to mitigate against future engine bay fires
- enhanced and requalified the AFSS to improve system reliability
- hot staging
- new electronic Thrust Vector Control (TVC) system for Super Heavy Raptor engines
- upgrades to the orbital launch mount and pad system: include significant reinforcements to the pad foundation and the addition of a flame deflector
I had trouble accessing it -- for a while, it didn't show me today's post (8 Sep 2023). So I'm going to take the liberty of pasting it here.
September 8, 2023
Upgrades Ahead Of Starship’s Second Flight Test
The first flight test of a fully integrated Starship and Super Heavy was a critical step in advancing the capabilities of the most powerful launch system ever developed. Starship’s first flight test provided numerous lessons learned that are directly contributing to several upgrades being made to both the vehicle and ground infrastructure to improve the probability of success on future Starship flights. This rapid iterative development approach has been the basis for all of SpaceX’s major innovative advancements, including Falcon, Dragon, and Starlink. SpaceX has led the investigation efforts following the flight with oversight from the FAA and participation from NASA and the National Transportation and Safety Board.
Starship and Super Heavy successfully lifted off for the first time on April 20, 2023 at 8:33 a.m. CT (13:33:09 UTC) from the orbital launch pad at Starbase in Texas. Starship climbed to a maximum altitude of ~39 km (24 mi) 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. This led to a loss of communications to the majority of booster engines and, ultimately, control of the vehicle. SpaceX has since implemented leak mitigations and improved testing on both engine and booster hardware. As an additional corrective action, SpaceX has significantly expanded Super Heavy’s pre-existing fire suppression system in order to mitigate against future engine bay fires.
The Autonomous Flight Safety System (AFSS) automatically issued a destruct command, which fired all detonators as expected, after the vehicle deviated from the expected trajectory, lost altitude and began to tumble. After an unexpected delay following AFSS activation, Starship ultimately broke up 237.474 seconds after engine ignition. SpaceX has enhanced and requalified the AFSS to improve system reliability.
SpaceX is also implementing a full suite of system performance upgrades unrelated to any issues observed during the first flight test. For example, SpaceX has built and tested a hot-stage separation system, in which Starship’s second stage engines will ignite to push the ship away from the booster. Additionally, SpaceX has engineered a new electronic Thrust Vector Control (TVC) system for 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 also made significant upgrades to the orbital launch mount and pad system in order to prevent a recurrence of the pad foundation failure observed during the first flight test. These upgrades include significant reinforcements to the pad foundation and the addition of a flame deflector, which SpaceX has successfully tested multiple times.
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 Starship’s first flight test. 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.--