posted 04-21-2023 05:14 PM               

With regards to the rocket, it appears that Stage 0 was one of the major contributing factors to the loss of engines. If you see some of the current pictures online, the reinforced concrete below the structure was turned into a crater. There are sections of it where the concrete was literally stripped away from the reinforcing steel bars.

It doesn't take a genius to figure out that a lot of debris was created by this, and that may well have knocked out the 3 engines that were shown to be inoperable just after launch. The debris could have further weakened the structural integrity at the base of the rocket leading to the other 3 engines going out while heading uphill.

posted 04-21-2023 05:33 PM               

Three months ago, we started building a massive water-cooled, steel plate to go under the launch mount. Wasn't ready in time and we wrongly thought, based on static fire data, that Fondag would make it through one launch.

Looks like we can be ready to launch again in one to two months.

posted 04-21-2023 07:36 PM               

quote:

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Originally posted by SkyMan1958:
It doesn't take a genius to figure out that a lot of debris was created by this, and that may well have knocked out the 3 engines that were shown to be inoperable just after launch.

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I am looking forward to the story the data tells. That is if SpaceX elects to share it. SpaceX is a private company with no obligation to report out to us the details. I am sure there will be a general reveal just to settle the public interest.

posted 04-23-2023 09:21 AM               

quote:

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Originally posted by Blackarrow:
...before Range Safety intervened.

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posted 04-24-2023 01:51 PM               

quote:

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Originally posted by Blackarrow:
And if the onboard FTS fails?

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For example to determine state of vehicle:

• AFTS - Receive GPS signal and processes position

• Legacy FTS - Range radar send out signal, transponder on rocket receives radar signal and responds with signal, Range radar receives transponder signal and processes position.

posted 04-29-2023 07:14 PM               

Musk: "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."

Musk: "I'm glad to report that the pad damage is actually quite small" and should "be repaired quickly."

Musk: "The vehicle's structural margins appear to be better than we expected, as we can tell from the vehicle actually doing somersaults towards the end and still staying intact."

Musk: From a "pad standpoint, we are probably ready to launch in 6 to 8 weeks."

"The longest item on that is probably requalification of the flight termination system ... it took way too long to rupture the tanks."

Musk: Time for AFTS [Autonomous Flight Termination System] to kick in "was pretty long," about "40 seconds-ish."

Musk: "There were three engines that we chose not to start," so that's why Super Heavy booster lifted off with 30 engines, "which is the minimum number of engines."

The three engines "didn't explode," but just were not "healthy enough to bring them to full thrust so they were shut down."

Musk: At T+27 seconds, SpaceX lost communications due to "some kind of energy event." And "some kind of explosion happened to knock out the heat shields of engines 17, 18, 19, or 20."

Musk: "Rocket kept going through T+62 seconds" with the engines continuing to run. Lost thrust vector control at T+85 seconds.

Musk: Generated a "rock tornado" under Super Heavy during liftoff, but SpaceX does not "see evidence that the rock tornado actually damaged engines or heat shields in a material way." May have happened, but "we have not seen evidence of that."

Musk: "It was actually good to get this vehicle off the ground because we've made so many improvements" in Super Heavy Booster 9 "and beyond."

"Really just needed to fly this vehicle and then move on to the much improved booster."

Musk: After AFTS, "the ship did not attempt to save itself."

Musk: Big thing for next Starship launch is "insuring that we don't lose thrust vector control" with Booster 9."

Musk: "We're going to putting down a lot of steel" under the launch tower before the next Starship flight.

"Debris was really just basically sand and rock so it's not toxic at all ... it's just like a sandstorm, essentially ... but we don't want to do that again."

Musk: "We certainly didn't expect" to destroy the concrete under the launchpad.

Musk: Speculating, but "one of the more plausible explanations is that ... we may have compressed the sand underneath the concrete to such a degree that the concrete effectively bent and then cracked," which is "a leading theory."

Musk: Reason for going with a steel plate instead of a flame trench is that for payloads in the rocket, the worse acoustic environment doesn't matter to the payload since it's about 400 feet away.

Musk: Flight was "pretty close to what I expected."

Musk: "Got pretty close to stage separation ... if we had maintained thrust vector control and throttled up, which we should have ... then we would have made it to staging."

Musk: "Our goal for the next flight is to make it to staging and hopefully succeed."

Musk: "My expectation for the next flight would be to reach orbit." Next flight profile will be a "repeat."

Musk: "The goal of these missions is just information. Like, we don't have any payload or anything -- it's just to learning as much as possible."

Musk: "Definitely don't" expect lunar Starship (under the HLS project) to be the longest lead item for the Artemis III mission.

"We will be the first thing to really be" ready.

Musk: Probably an 80% probability of reaching orbit with Starship this year, and "I think close to 100% chance of reaching orbit within 12 months."

Musk: Slowed down Raptor engine production "because we've got more Raptors than we know what to do with."

Musk: Expect to spend ~$2 billion this year on Starship.

Musk: "We do not anticipate needing to raise funding ... we don't think we need to raise funding." Will do the "standard thing where we provide liquidity to employees."

"But to my knowledge we do not need to raise incremental funding for SpaceX."

Musk: For the next flight, "we're going to start the engines faster and get off the pad faster." From engine start to moving Starship "was around 5 seconds, which is a really long time to be blasting the pad." Going to try to cut that time in half.

Musk: Starship didn't get to what SpaceX thought was "a safe point to do stage separation."

Musk: "I thought the SpaceX team did amazing work."

"This is certainly a candidate for the hardest technical problem done by humans."

Musk, on environmental response: "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."

Musk: SpaceX has yet to make a final decision on which Starship prototype and Super Heavy booster will fly the next launch.

Musk: "Going to be replacing a bunch of the tanks in the tank farm, but these are tanks that we wanted to replace anyway."

Musk: "Tower itself is in good shape. We see no meaningful damage to the tower even though they got hit with some pretty big chunks of concrete."

Musk: Starship sliding laterally off the launchpad was "because of the engine failures."

posted 05-01-2023 09:31 AM               

quote:

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Originally posted by perineau:
...perhaps the technology is still too complex 54 years later.

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Thirty-three is only six more than the 27 that worked successfully on last night's Falcon Heavy launch.

quote:

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Originally posted by Space Cadet Carl:
I kept thinking about the old Soviet N-1 problems

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posted 05-01-2023 02:46 PM               

Falcon Heavy is actually three separate boosters with nine engines each that are essentially lashed together. Has SpaceX ever stated that they would launch a Falcon Heavy with one, two or three engines out? I do not recall hearing so. But they are on record stating that they would go ahead with a Super Heavy launch with up to three non-working engines (although that may change).

Robert has already described the difference in steering between N-1 and Super Heavy. And that is a valid divergence.

posted 05-02-2023 01:32 AM               

quote:

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Originally posted by Headshot:
so far, the only historical corresponding data point is the N-1.

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SpaceX has demonstrated their design iterations along the way and there are numerous people documenting the development of the vehicles, infrastructure, and hardware.

The number of engines that Super Heavy has at the moment is a result of how much thrust each engine can develop and how much mass the system is designed to lift.

SpaceX has changed the number of engines and the layout many times during the design evolution and may not have yet settled on a final number.

posted 05-02-2023 08:28 AM               

quote:

---

Originally posted by Headshot:
The harmonics and vibrations of such a changing (as engines go out or come back on line) complex system have got to be formidable (as must be the plumbing) and, so far, the only historical corresponding data point is the N-1.

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The N1 is not relevant. It had QA and internal FOD issues. Its engines were a cycle that was susceptible to FOD. It had an engine control system that wasn't fully validated. It used a unique method of flight control.

The number of engines on Starship are dictated by:

1. Using the same engine on the upper stage and booster
   
2. The ability of the upper stage to deal with an engine out
   
3. The ability of both stages to land. This meant six engines on the upper stage with three for landing and 33 engines on the booster with 13 for landing.

posted 05-18-2023 10:33 AM               

Ship 25 moved to a suborbital pad at Starbase for an upcoming static fire of its six Raptor engines.

posted 05-28-2023 06:43 PM               

Starship gave us quite a show during the first flight test of a fully integrated Starship (S24) and Super Heavy rocket (B7) from Starbase in Texas.

On April 20, 2023 at 8:33 a.m. CT, Starship successfully lifted off from the orbital launch pad for the first time. The vehicle cleared the pad and beach as Starship climbed to an apogee of ~39 km over the Gulf of Mexico – the highest of any Starship to-date.

With a test like this, success comes from what we learn, and we learned a tremendous amount about the vehicle and ground systems today that will help us improve on future flights of Starship.

posted 06-27-2023 09:44 AM               

Key milestone completed for flight 2.

posted 07-20-2023 04:13 PM               

Starship Super Heavy Booster 9 transported to the orbital launch pad at Starbase for testing ahead of flight.

posted 07-21-2023 04:24 PM               

Booster 9 on the pad.

posted 07-28-2023 05:42 PM               

Full-pressure test of Starship flame deflector.

posted 08-04-2023 03:13 PM               

Booster 9 completed a flight-like chill and spin of the Raptor engine pumps in advance of static fire.

posted 08-06-2023 02:31 PM               

View of Starship Super Heavy Booster 9 static fire.

posted 08-18-2023 09:55 PM               

Vented interstage and heat shield installed atop Booster 9. Starship and Super Heavy are being upgraded to use a separation method called hot-staging, where Starship’s second stage engines will ignite to push the ship away from the booster.

posted 08-23-2023 02:18 PM               

On approximately September 8, 2023, mariners operating offshore in waters east of Brownsville, Texas, are advised of rocket launching activities and associated hazardous areas which may impact navigation interests.

posted 09-06-2023 11:04 AM               

Fully stacked Starship on the launch pad at Starbase.

posted 09-06-2023 07:55 PM               

The SpaceX Starship mishap investigation remains open. The FAA will not authorize another Starship launch until SpaceX implements the corrective actions identified during the mishap investigation and demonstrates compliance with all the regulatory requirements of the license modification process.

posted 09-08-2023 10:27 AM               

FAA Closes SpaceX Starship Mishap Investigation

The FAA has closed the SpaceX Starship Super Heavy mishap investigation. 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.

posted 09-10-2023 01:54 PM               

Congrats to SpaceX for completing and document[ing] the 57 items required by the FAA for Flight 2 of Starship!

Worth noting that 6 of the 63 items refer to later flights.

posted 09-10-2023 02:13 PM               

For the six Future Action issues, shouldn't SpaceX have indicated either a target date or a flight test number by when these issues will be complete?

posted 09-15-2023 06:32 PM               

SpaceX conducted a test flight of the Starship/Super Heavy at Boca Chica, TX on April 20, 2023. As a result of that launch, SpaceX completed a mishap investigation with FAA oversight; this investigation analyzed the launch, mishap events, and corrective actions. Before it is authorized to conduct a second Starship/Super Heavy launch, SpaceX must obtain a modified license from the FAA that addresses all safety, environmental, and other regulatory requirements.

As part of that license application determination process, the FAA will review new environmental information, including changes related to the launch pad, as well as other proposed vehicle and flight modifications. The FAA will complete a Written Reevaluation (WR) to the 2022 Programmatic Environmental Assessment (PEA) evaluating the new environmental information, including Endangered Species Act consultation with the U.S. Fish and Wildlife Service.

If the FAA determines through the WR process that the contents of the PEA do not remain valid in light of the changes proposed for Flight 2, additional environmental review will be required. Accordingly, the FAA has not authorized SpaceX's proposed Flight 2.

The FAA will provide updates with notification of any license determination or results of additional environmental review.