SpaceX SpaceX Starship development: 7th flight January 10

[mfb]

Looks like SpaceX was working on a water-cooled steel plate already, but didn't expect to need it for a first test flight:



Here is a slow-motion video of the liftoff from the tower, with some boulders flying in the background:

 

[nsaspook]

 

[nsaspook]

That ship was fighting all the way up to the end.

 

[gleem]

The launch pad, what a mess

Outside of the crater, what other damage might be present? Musk says 1 to 2 months before the next launch attempt. it seems like a lot more to me. How about a completely new one?

 

[mfb]

The floor should be relatively easy to repair.

The chopsticks have moved again, they look fine overall. Debris strikes to the upper part of the launch mount could be the most time-consuming issue.

 

[Tom.G]

Well, Starship got off the ground, but also scatterd a bunch of it!

Excerpt from Los Angeles Times, Thu. Apr. 27, 2023, page A10

[bold] SpaceX launched concrete chunks far away. [/bold]

...[ scattered ] pulverized concrete up to 6.5 miles NorthWest of the launchpad and resulted in about 385 acrers of debris on SpaceX's facility and at nearby Boca Chica State Park...

...many large cocncrete chunks, stailesss-steel sheets, metal and other objects were "hurled thousands of feet away."...

...A 3.5-acre fire also started on Boca Chica State Park, south of the launchpad, the agency (U.S. Fish and Wildlife Service) said.

 

[Astronuc]

Massive, exploded SpaceX rocket devastated a town and a wildlife reserve — and locals are furious

But the community living near the launch site has been dealing with fallout from the launch, in both senses of the word. The explosion essentially obliterated the launch pad, carving a massive crater and sending chunks of concrete, sheets of stainless steel and other debris flying into the ocean on Boca Chica Beach. A Dodge Caravan was smashed with wreckage, which the U.S. Fish and Wildlife Service reported was scattered over 385 acres, causing a fire that burned 3.5 acres on Boca Chica State Park land.

Clouds of ash and particulates rained down on residents of Port Isabel, about six miles away, settling onto homes, cars, and streets, breaking several windows. It's not clear if the particulate matter is dangerous to breathe or touch, or if it will pollute the soil.

https://www.msn.com/en-us/news/tech...fe-reserve-and-locals-are-furious/ar-AA1auxQJ

Seems rather sloppy and unnecessary. I understand the desire to launch and cut corners, but there is a 'right way' to launch a rocket, as has been demonstrated over the past 6+ decades, e.g., at Cape Canaveral, aka Kennedy Space Center.

 

[berkeman]

Seems rather sloppy and unnecessary.

Sloppy and clumsy. Unfortunate.

 

[mfb]

Massive, exploded SpaceX rocket devastated a town and a wildlife reserve — and locals are furious

A bit of sand and dust falling down does not "devastate a town", nor do some chunks of concrete falling down "devastate a wildlife reserve". It's sand and concrete parts, they are not toxic. The headline is absurd.

No one was harmed, and no significant damage was found outside of SpaceX's property besides a few broken windows - and I haven't seen a confirmation that these refer to windows of building, not windows of cars parked close to the launch.

If you would put the rocket horizontally and rotated it around one end it would cover an area of 11 acres. The wildfire was 1/3 of that area, and it's in a region that has frequent natural fires anyway - if it's not started by a rocket then a thunderstorm will ignite the same stuff.

Seems rather sloppy and unnecessary.

The sloppy part is on the side of the reporters trying to blow this story up more than the rocket.

but there is a 'right way' to launch a rocket, as has been demonstrated over the past 6+ decades, e.g., at Cape Canaveral, aka Kennedy Space Center.

The maiden flight of the Saturn V (Apollo 4) also damaged the launch pad significantly and threw debris around. Here is a report, damage to the pad is described on page 3-15. Back then we just didn't have 2135 cameras inspecting every centimeter of the area and the internet to show these pictures to everyone within an hour. Back then news focused on the rocket.
Some debris flying around from Apollo 8 and fires in the launch tower.

 

[Rive]

The maiden flight of the Saturn V (Apollo 4) also damaged the launch pad significantly and threw debris around.

Exactly because of that (that we know what should be expected, for 50+ years already ) why this was so gross.

Big rocket does not match well with oversized sloppy stools as 'launch pads'.

I hope the next one will be something more decent.

 

[Astronuc]

No one was harmed, and no significant damage was found outside of SpaceX's property besides a few broken windows - and I haven't seen a confirmation that these refer to windows of building, not windows of cars parked close to the launch.

I would agree that the headlines are hyperbolic, which is unfortunate and disappointing.

PORT ISABEL, Texas (ValleyCentral) — Residents in Port Isabel are reporting small particles of debris are falling from the sky after this morning’s SpaceX launch at Boca Chica Beach.

Port Isabel Police Chief Robert Lopez said the particles “looked a lot like gunpowder.”

A caller who resides in Port Isabel told ValleyCentral everything in the city looks like it is covered in dust.

https://www.valleycentral.com/news/...idents-report-particles-falling-after-launch/

Port Isabel spokeswoman Valerie Bates told The New York Times that most of the city was covered with a thick, granular sand that landed on everything.

"It was truly terrifying," said Sharon Almaguer. She was home with her 80-year-old mother when her brick house shook from the rocket explosion.

The Cameron County Emergency Management Division confirmed the debris was sand and soil from the SpaceX launch.

https://www.upi.com/Science_News/2023/04/21/SpaceX-starship-rains-debris-Port-isabel/1451682102059/

https://www.tpr.org/technology-entr...rticulates-spacex-explosion-rio-grande-valley (Images of a vehicle in Port Isabel covered in particulate matter - from the owner in Port Isabel) It's probably not toxic, but then one would not want to inhale mineral dust.

Articles do not indicate if the particulate/dust/debris are from the launch (launch pad damage) or from the explosion of the rocket. I would think that at 4 minutes the rocket would be down range over the Gulf of Mexico away from Port Isabel. Port Isabel is about 5-6 miles to the NNW of SpaceX launch site, so not in the direction of the rocket trajectory.

The Federal Aviation Administration said SpaceX violated its launch license by not ensuring “far field blast overpressure” was within regulation, Reuters reported, . . . .

https://www.portisabelsouthpadre.co...tivity-debris-concerning-activists-officials/

Still waiting for reports of broken windows in towns outside of SpaceX site.

Waiting for FAA statement on investigation into SpaceX mishap.
https://www.faa.gov/space/stakeholder_engagement/spacex_starship
https://www.faa.gov/space/compliance_enforcement_mishap

 

[mfb]

Some more information about the flight timeline:
SpaceX to spend about $2 billion on Starship this year, as Elon Musk pushes to reach orbit

Video of a Twitter Spaces discussion and some highlights on Twitter:

Three engines showed abnormal readings so they were not started at takeoff. The rocket can reach orbit missing three engines. So far no evidence that debris damaged the rocket significantly.
Some explosion after 27 seconds damaged four engines and the rocket lost thrust vector control 85 seconds into the flight. That later lead to the spin of the rocket.

The next flight will have a water-cooled steel plate under the launch mount and will also take off faster. The plate was already in preparation but SpaceX expected the concrete pad to survive (at least to the point where it doesn't fly everywhere).

 

[mfb]

Crater has been filled in, rebar is being fixed. We don't know how many of the wires, pipes, valves and so on need attention, but the obvious damage to the ground is largely gone after two weeks:

 

[artis]

Don't wish to sound like mr. Wise guy or mr. "told ya so" but rockets with far less thrust and less engine exhaust require water spray jets to save the launchpad so that it can be reused without repairs. NASA knows this, everyone knows this, it's been practically tested.

How in the world anyone at SpaceX thought that this rocket would not absolutely obliterate everything below it especially without a waterjet or whatever flame retarder , I just don't get it.

I would understand the wish to rush forward without delays and then repair whatever damage comes afterward but thinking such a launch wouldn't cause serious damage is simply not imaginable.

+ what if the debris that was flying around due to missing retarders hit the rocket itself or the launch pad and then caused damage or possibly failed the whole launch itself?
I mean I really don't understand this part, it seems somewhat reckless to me.
Here is a video documenting the debris that flew off from the launchpad, pretty serious if you ask me.
Steel rebar chunks littered like needles in a haystack , those things could have easily hit something of value on the very launch site itself.
The debris part is on the second part of the video


Now I am not among those that care for speculative titles or hype but from that video it can be clearly seen the whole laucnh site is just covered with smaller and larger holes and dents and buckled metal, + the whole area is covered with rebar and concrete, sure enough I do not believe it is toxic or anything, it's not radioactive or anything but it will require quite a bit of human effort to clean it all up and I still don't see why that was necessary.

 

[artis]

On a more general note , this rocket seems eerily similar to the less known Soviet Union's moon mission attempt rocket N1, maybe not in visuals but in the many parallel engine count, N1 first stage had 30 engines (NK-15 later 33) while starship has 33 Raptors.
Back then in the 60's the soviets had problems with reliably running so many parallel engines,
I do wonder , although technology has advanced quite a bit as has diagnostics , can Space X or anyone for that matter run so many parallel rocket engines reliable even now?

It seems you can only lose "x" number of engines before the rocket becomes unstable + even if you don't lose any engine but one say explodes that has the tendency to take out others and then you all of a sudden lose many engines and again become unstable.
The only success that came out of the soviet N1 was it's advanced rocket engine (advanced for it's time) the NK-15 later upgraded to NK-33 which was used even after the 2000's by American company making the Antares rockets as NASA contractor. Out of it's physics then came the RD-180, also an oxygen rich engine , more advanced that the Russians sold to US for use in Atlas V launch vehicles.
Anyone interested can simply google these and see for himself.

Anyway IIRC starship seems to me to be the second only attempt in history to make a functioning rocket out of so many parallel engines and the first attempt failed by the soviets, it will be interesting to see whether this time it will come to pass.

 

[Rive]

starship seems to me to be the second only attempt in history to make a functioning rocket out of so many parallel engines

Just for the log: Falcon Heavy has 27 engines.

 

[artis]

Just for the log: Falcon Heavy has 27 engines.

Ok I missed that , haven't followed that closely to latest advancements in rocket engineering.
So Soviet N1, Space x's Falcon and starship , are there any others?

 

[gleem]

Don't wish to sound like mr. Wise guy or mr. "told ya so" but rockets with far less thrust and less engine exhaust require water spray jets to save the launchpad so that it can be reused without repairs. NASA knows this, everyone knows this, it's been practically tested.

They intend to use a steel water jacketed plate to dissipate the heat. The engines generate over 90 GW of heat. I would suppose you don't want to generate steam in the jacket. Steel is a poor conductor of heat. This plate is about 10m in diameter. Even if say 10% of the heat is transferred to the jacket you need to absorb 9GW for about 3 seconds. The water in the plate will be in there for several seconds at least for a surface temperature of several thousand degrees C. If bubbles form at the surface of the plate will the plate buckle or melt?

Musk always talks about using the simplest solution with minimum parts. A water deluge/flame trench system seems like the best KISS solution.

And then there is no sound abatement.

Good Luck.

 

[russ_watters]

Don't wish to sound like mr. Wise guy or mr. "told ya so" but rockets with far less thrust and less engine exhaust require water spray jets to save the launchpad so that it can be reused without repairs. NASA knows this, everyone knows this, it's been practically tested.

How in the world anyone at SpaceX thought that this rocket would not absolutely obliterate everything below it especially without a waterjet or whatever flame retarder , I just don't get it.

I would understand the wish to rush forward without delays and then repair whatever damage comes afterward but thinking such a launch wouldn't cause serious damage is simply not imaginable.

I don't like the apparent shoot-from-the-hip approach either, but presumably NASA did review and approve the pad design/construction prior to launch.

 

[russ_watters]

Musk always talks about using the simplest solution with minimum parts. A water deluge/flame trench system seems like the best KISS solution.

And then there is no sound abatement.

I'd been under the impression that the water deluge was more/exclusively for sound abatement. Maybe they calculated they didn't need it.

 

[gleem]

Cape Canaveral is next to Merritt Island national wildlife refuge so sound abatement would be desirable not to affect the wildlife greatly.

Starbase at Boca Chica TX is 1 mile from the Las Palomos wildlife management area and 2 miles from the Boca Chica wildlife refuge. With a water deluge system, the Saturn V generates a sound level of 145 dB (pain threshold for humans) at two miles. Spectators are kept more than 5 miles from the launch pad. Why noise abatement conditions have not been imposed seems strange.

With no noise abatement and twice the power, the noise levels will be higher.

Maybe they calculated they didn't need it.

Do you think they would do it for a few birds and turtles?

 

[artis]

@gleem I did not know that the total heat output of those engines was 90GW, but i can't find any reference for that either , can you please post some?

Either way Elon's remarks about a "steel plate" do sound somewhat humorous.

From what I understand the waterjet is there not so much for sound dampening but for the rapid cooling of the exhaust flame/gas so that it doesn't behave like a welding plasma torch vaporizing and cutting everything in it's path.
Take a propane oxygen gas torch cutter and then introduce a water spray to traverse the flame and you should get it to stop being effective at cutting.

At least that's how I always understood it, a cooling mechanism to save the foundation structures and lessen the escaping flame damage and velocity.

 

[russ_watters]

With no noise abatement and twice the power, the noise levels will be higher....

Do you think they would do it for a few birds and turtles?

By "sound" I thought we really meant "vibration". Harmful to the spacecraft.

https://en.m.wikipedia.org/wiki/Sound_suppression_system

 

[gleem]

@gleem I did not know that the total heat output of those engines was 90GW, but i can't find any reference for that either , can you please post some?

I got 120 MHp from somewhere on the web for the total HP of the Starship which I can't remember and converted it to watts. However, I can show a direct calculation using space X fuel consumption of 194kg/sec/engine which gives a higher heat output.

1 mole CH4 produces 890.4 Kj of heat.
There are 22.7 moles in a kg of CH4
The engine uses 194kg/sec × 22.7moles/kg ×890.4 Kj/mole =3.92 x10⁹ j/sec
With 33 engines a total heat production of 129.4 Gw.

but not all that heat is transferred to the earth.

From what I understand the waterjet is there not so much for sound dampening but for the rapid cooling of the exhaust flame/gas so that it doesn't behave like a welding plasma torch vaporizing and cutting everything in it's path.

from https://en.wikipedia.org/wiki/Sound_suppression_system

Sites for launching large rockets are often equipped with a sound suppression system to absorb or deflect acoustic energy generated during a rocket launch. As engine exhaust gasses exceed the speed of sound, they collide with the ambient air and shockwaves are created, with noise levels approaching 200 db.

By "sound" I thought we really meant "vibration". Harmful to the spacecraft.

That is the biggest concern I am sure but 145 dB at two miles with a water deluge is very "loud" and the Starship test broke windows in Port Isabel 6 miles away.

 

[mfb]

How in the world anyone at SpaceX thought that this rocket would not absolutely obliterate everything below it especially without a waterjet or whatever flame retarder , I just don't get it.

SpaceX has taken risks with test articles frequently - often it works (despite "everyone" claiming it cannot work in advance) and ends up being a great solution. In the rare cases where it doesn't work everyone has to shout how SpaceX is stupid, of course.

It's likely the launch pad would have survived quite well if the launch wouldn't have crushed the soil beneath the concrete plate. Well enough for a test flight - the long-term solution was already in production but not ready yet.

Water reduces the sound level somewhat, but there is no indication that sound levels were a problem for the launch. Same as for the plate, will be available for future launches, but wasn't seen as necessary for the first launch (rightfully in this case). Saturn V didn't use a sound suppression system by the way. There are a couple of others that don't have one, too.

Interestingly, a flame trench increases sound levels in most places. The engine exhaust accumulating below the rocket without one leads to some cancellation.

Starship can do its mission even if three engines are out throughout the whole flight. Losing more engines later can be acceptable, it depends on the details which engines stop when. A large number of engines leads to more redundancy. Long-term we'll likely see engine failure rates of the order of 0.1%, typical for established engines. If you have 5 engines then you need all 5, that gives you a 0.5% risk to lose the rocket. The risk to lose 4 or more engines out of 33 is just 1 in 25 million.

Either way Elon's remarks about a "steel plate" do sound somewhat humorous.

We have pictures of the steel plate they are building. The components were already spotted before the Starship test launch.

 

[Rive]

SpaceX has taken risks with test articles frequently

So often that I can't help to suspect that they are cutting cost on disassembly and disposal this way

The awful number of half-baked proto- and demo-pieces are just an inevitable byproducts of their development strategy.

 

[artis]

SpaceX has taken risks with test articles frequently - often it works (despite "everyone" claiming it cannot work in advance) and ends up being a great solution. In the rare cases where it doesn't work everyone has to shout how SpaceX is stupid, of course.

I'm not saying their stupid, and am not among those that enjoy seeing others fail, anyone who tries hard enough long enough, eventually succeeds or at least gets valuable experience.

What I am saying though is with a rocket like this even without calculation one can be sure there will de destruction of the launch site without proper retarders, absorbers, jets, flame tunnels etc.

Maybe Elon has calculated that rebuilding the site is cheaper than making it reusable in the first place, not sure.
Clearly I do not have the info about the expenses of the project and site and how much for rebuilding although I would estimate that judging by the extensive damage and debris scattering it will cost some money to clean it all up and rebuild.

 

[artis]

So often that I can't help to suspect that they are cutting cost on disassembly and disposal this way

Are you implying that their allowing stuff to blow up on purpose so that no one has to unscrew the bolts and dispose of the materials afterwards?

Either way the huge amount of debris scattered after this launch ain't just gonna disappear on it's own so they will have to pay the guys who will eventually go in and take that scrap out.

 

[Rive]

Are you implying

I'm just ... thinking that while proper disposal of a no longer useful proto of this size is a royal pain in ***, as an alternative they may have considered the ... entertainment value of the thing parallel with the inevitably limited gains from one such test ...

And, to be clear: this thought is not exactly a derogative one.

 

[mfb]

I'm not saying their stupid

Are you sure?

What I am saying though is with a rocket like this even without calculation one can be sure there will de destruction of the launch site without proper retarders, absorbers, jets, flame tunnels etc.

SpaceX did the calculations and estimated that the launch pad would survive. You claim you could have known otherwise before the launch. Without even doing a calculation yourself!