On Saturday evening, SpaceX CEO Elon Musk took to Twitter to give an update on the Starship Flight Test which took place on April 20th, 2023, and to provide insight into the future of the program.

Flight One - What Happened?

The root of the issue lies in Booster 7's 33 Raptor 2 engines and 2 HPUs which experienced multiple anomalies on the pad and in flight.

Prior to flight, the SpaceX team made the decision to disable 3 of the 33 Raptor engines on B7, as opposed to aborting the launch. This decision, while risky, was not what caused the loss of the vehicle, but rather a series of issues in flight - primarily involving Thrust Vector Control (TVC), a system which is vital to  steering the vehicle in flight.

It all started to go south at T+27 seconds into flight when engine 19 "lost comms" (exploded) due to "some kind of energy event.", and damaged the shielding in engines 17-20. Despite having multiple engines down, B7 continued its flight, then, at T+62s, they observed damage to engine 30s shielding. The flight continued for 23 more seconds before all hope was lost, when engine 6 was lost, and thus all TVC capability was jeopardised for the vehicle as a result of this.

Regarding the Flight Termination System, Musk says "The longest item on that [requirements to next launch] is probably requalification of the flight termination system", adding "it took way too long to rupture the tanks.". Elon later states that it was triggered shortly into the unplanned tumble, but took "40 seconds-ish" to rupture the tanks.

Musk also responded to questions about the Ship attempting to salvage itself following booster termination, which he says they have not seen any data suggesting it did attempt to and "that's not what the ship should have been attempting to do,".

Musk says the liftoff generated a "rock tornado" under the booster, but it is not expected to have caused any damage to the Raptor engines or pad.

Elon also says that Booster 7 did not throttle to compensate for the failing engines, which, if it had, Musk believes staging would have been achieved. 

Stage Zero

Stage zero (the pad) is mostly in-tacked following the launch, Musk says the amount of damage is "actually quite small", and should "be repaired quickly", quoting a timeline of 6-8 weeks. The OLM and launch tower are in good condition despite the unplanned power slide by the vehicle.

SpaceX believes the pad "bent" due to the Fondag concrete shattering then sand underneath compressing, explaining the crater below the OLM.

Environmental Damage

Musk says when questioned about the possibility of a lawsuit by environmentalists: "The rocket uses non-toxic propellants and ... scattered a lot of dust, but to the best of our knowledge there has not been any meaningful damage to the environment that we're aware of."

Moving Forward

As with any launch anomaly, SpaceX and the FAA are conducting a joint investigation into the failure, but Elon has outlined a number of vehicle and pad changes planned moving forward:

Pad

• Thick water-cooled steel plate will be installed under the OLM and connected to the legs for support
• Vertical GSE tanks in the Orbital Tank Farm will be replaced with horizontal tanks, as was always planned

Vehicle

• B9 expected to perform the flight, with a multitude of upgrades including E-TVC
• Supporting ship is currently TBD, decision expected next week
• Engines will be ignited later in the countdown, roughly half from 5 to 2.5 seconds
• Goal for flight 2, which will follow the same flight plan as flight 1, is to achieve staging and hopefully "reach orbit" (although loosely defined, as it will be the same trajectory as flight 1 was planned to)

Musk notes that Starship will be ready for Artemis II, but stutters while saying "We will be the first thing to really be [ready]". He also notes there is an 80% chance of Starship reaching orbit this year, and a "100% chance" in the next 12 months.

Remarks On Success

Musk says "The outcome was roughly in what I expected, and maybe slightly exceeding my expectations, but roughly what I expected, which is that we would get clear of the pad.", later adding that the structural integrity of the stack "appear to be better than we expected, as we can tell from the vehicle actually doing somersaults towards the end and still staying intact.".

Later in the call Musk says "I thought the SpaceX team did amazing work.", "This is certainly a candidate for the hardest technical problem done by humans."