Why 33 raptor engines testing is a BIG PROBLEM for SpaceX and Elon Musk?

Why 33 raptor engines testing is a BIG PROBLEM for SpaceX and Elon Musk?
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Building a spacecraft is no mere feat. It involves lots of testing before it can launch. While the FAA won't allow SpaceX to test launch the Starship if SpaceX can't complete 75 actions, SpaceX has to be sure that the 33 raptor engines at the bottom of Super Heavy will fire without any significant problems first.
So, why a 33-raptor engine testing is a big problem for SpaceX and Elon Musk?
Let’s expose all of this in today's episode of the Alpha tech channel:

SpaceX is now looking forward to completing an orbital test flight. This will be a test flight like no other, as a fully stacked Starship will produce almost double the thrust of the Saturn 5, the most powerful rocket ever made. In order to produce this amount of thrust, the Super Heavy booster will have 33 raptor engines, lifting the Starship’s second stage into orbit. In order for this test flight to go well, an enormous amount of engine testing needs to be done.
But this is really a big deal.
After the latest explosion of Booster 7, Elon Musk also admitted that:" Going forward, we won’t do a spin start test with all 33 engines at once."

The most obvious is simple enough: For a test with 33 Raptors, SpaceX needs to fully fill a Super Heavy booster for the first time. Depending on the storage situation, that process will likely begin by filling Booster 7 with about 2500 tons of liquid nitrogen– about two-thirds full. If SpaceX also temporarily fills one of the orbital tank farm’s liquid oxygen (LOx) or methane (LCH4) tanks with nitrogen, it could fully load Booster 7 with around 3500 tons of nitrogen. At least according to SpaceX’s own website, that’s about the same weight as the propellant (3400t) Super Heavy is designed to lift off with.
If that full test goes well, SpaceX will then likely perform one or several wet dress rehearsals, ultimately filling Booster 4 with approximately 2900 tons of cryogenic oxygen and 500 tons of cryogenic methane.
Why 33 raptor engines testing is a BIG PROBLEM for SpaceX and Elon Musk?

[Antares]

I can't understand how they expect to be able to do this with no flame diverter pit and no sound suppression water system. The acoustics of placing a rocket directly above a flat concrete slab like that will likely destroy everything.

[executivesteps]

Looking at all the ground work this project still needs before attempting a launch it’s become obvious that the FAA review never interfered with Musk’s launch schedule. He just wasn’t ready.

[markgardner]

The Soviets discovered that putting many rockets on the N-1 booster did not work out. I am thinking SpaceX needs to rethink their booster format with fewer bigger rockets, perhaps as few as 16 or 20. Still would give redundancy if they need to throttle back or shut down a rocket engine on launch or landing. The more complicated you get, the more likely you are to have a failure, perhaps catastrophically.

[DavidPennable]

Elon could solve the gas buildup with a bunch of his Tunnel H-VAC systems.

[juliancrooks]

The Russians tried a similar design in the late 60s called the N1 . It didn't end well as it blew up the whole launch complex. I hope they have a better outcome.

[otpyrcralphpierre]

I think that the lack of a flame diverter is a critical mistake.

[mikem]

To test they don't need to fully fill to do basic tests. And testing 15 at a time just doubles amount of testing. It's very unlikely they will fully fuel till first test launch. Bring me news not guesswork.

[executivesteps]

Btw The Soviet N1 was the most powerful rocket ever made.

[SubmitTheKraken]

Guy tries to lift a building and bring it to another planet, most epic project ever.

[xponen]

if SpaceX remove the reusable goal will the booster use less engine? because you said it was for redundancy so obviously that is for landing, as Saturn 5 only need 4 engine, they could just do the same thing.

[rickster]

I don't see any big problems. Test, learn, and make changes. Retest, learn some more, and make more changes. Simple.

[silvadelshaladin]

You don't want to make a crater when launching from a mobile platform.

[gregorysagegreene]

Booster "two thirds full" of propellant, at 2500 ton, is over 60 fully laden semi truckloads of gas ... astronomical!
So, close to a 100 truckloads full - crazy.

A 'light' truck load of propellant, 25 ton,
burnt at liftoff, e v e r y second!

This is fantastic, but here's another thought: I had been thinking that Starship might be a great cargo transportation system for coast to coast pallet shipping in just a half hour instead of 2.5 to 5.0 days. But, being only capable of holding a 100 ton of freight, 2.5 full semi truck loads, vs requiring over a 100 truckloads of fuel, this is a 40 to 1 hauling ratio ... vs a current semi truck has a ratio of around 0.44 - i.e: 17.5 ton tractor & empty trailer vs 40 ton when fully loaded. So, rockets maybe not an ideal point-to-point solution just yet, unless drastically-reduced ground time is factored in ... in which case you get a minimum 120x benefit factor (2.5 days * 24 hours / 0.5 hr) to add in to the calculation ... brings it down to 0.33 to 1 ?

[astrogeo]

This seems like a quite balanced evaluation of the challenges facing the first full booster/starship rocket launch. It seems tough, I hope SpaceX can get through this. I wonder how much time and work would be needed on the follow-up launches to the first. Are they able to cut down the testing to a viable level? As Musk wants the turnaround for the next launch to be almost like an airliner, they need to cut it down to an absolute minimum. It was the lack of testing of the reentry flightworthyness of the Space Shuttle that killed the 7 astronauts and doomed the Shuttle in the long run. So getting the right balance seems a very tough going. Let's hope it's better performed than what NASA managed, but this could be a dramatic ride - at least with the hardware only.

[VictorLarsen-fyls]

Are you laughing? A volumetric explosion under the rocket tore off part of the engine covers, and Musk says there were no serious damage. 🤣The launcher did not have a drain to remove flammable gases and there were sources of open fire - this is ingenious.

[NeverTalkToCops]

Farm silos. What a lashup. There will be unforeseen instabilities and possible sound suppression failure.

[jojoeverycat]

the idea of buddled 33 rocket engines deem to post the never-ending safety issues due to the permutation of variables in engineering numerical simulation far too overwheming the computation capability of the present control system. With this type of rocket design, it is already proned to multiple-correlatable failure which can only be analyzed and completely overrided at a mind-blowing nano seconds using AI-based expert logics .

[richardlong]

They will have to test all 33 @ some point before actualy launching this ginourmouse thing before ever putting people into it as well... I would definetly rather see explosions without humans on board...

[russchadwell]

"Wow, a test of thirty nine Raptors.."

Did I mishear that?

[rcpmac]

Refreshing to hear an actual grownup speak to the realities of spacex challenges rather than the typical drooling fanboy commentary one hears on most channels.