totm nov 2023 SpaceX Discussion Thread

[tater]

 

[kerbiloid]

8 hours ago, sevenperforce said:

If you make it wider, then it carries more propellant, which makes it heavier.

Then you make it proportionally shorter, and it weights fine.

8 hours ago, sevenperforce said:

To the contrary, Raptor 2 has thrust levels significantly higher than what was estimated when the booster diameter was set.

And they still need a skirt. So, even Raptors 2 don't fit its diameter.

Thus, Raptor 1 looks unable even to lift it, and the diameter looks overoptimistically.

8 hours ago, sevenperforce said:

The cutouts in the stiffener ring are attached to secondary stiffener rings wrapped around each engine. 

The cutouts have a visible gap to prevent the contact of the nozzle and the ring.
The nozzles are attached to the combustion chamber, not to the ring.

And anyway the cutouts weaken the ring and would not be planned, unless being forced to by the already existing tank design.

On 2/12/2022 at 3:19 AM, Lukaszenko said:

I didn't really understand the part where Elon said they're having problems keeping the combustion chamber from melting. Like...what? That seems kind of critical. How do you have an apparently working and even flying engine where the combustion chamber melts? And then, how do you start mass-producing it before fixing this seemingly not-so-small issue?

 

I believe, the SpaceX engineers know what they do much better than we can estimate their engine quality.

On 2/12/2022 at 4:01 AM, RCgothic said:

An engine that melts at 340bar and 250tf thrust will be fine at 320 bar and 230tf thrust.

Then why call it "problems"?

Of course, where the engines are put close to each other, they shade each other, so the cooling area gets decreases twice in the real rocket, rather than on the test stand.

Looks like they faced the problem of Raptor 1 overclocking, making it possible to lift this rocket at all.

Just a side note

https://3dnews-ru.translate.goog/1026699/glavniy-ingener-raketnih-dvigateley-spacex-pokinul-kompaniyu-ilona-maska?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=ru

 

Edited February 13, 2022 by kerbiloid

[Beccab]

 

[KSK]

9 hours ago, CatastrophicFailure said:

Burns more than the real thing... 

Yeah, Coke always gives me acid reflux too.

[Rakaydos]

7 hours ago, kerbiloid said:

Then you make it proportionally shorter, and it weights fine.

And they still need a skirt. So, even Raptors 2 don't fit its diameter.

Thus, Raptor 1 looks unable even to lift it, and the diameter looks overoptimistically.

The cutouts have a visible gap to prevent the contact of the nozzle and the ring.
The nozzles are attached to the combustion chamber, not to the ring.

And anyway the cutouts weaken the ring and would not be planned, unless being forced to by the already existing tank design.

I believe, the SpaceX engineers know what they do much better than we can estimate their engine quality.

Then why call it "problems"?

Of course, where the engines are put close to each other, they shade each other, so the cooling area gets decreases twice in the real rocket, rather than on the test stand.

Looks like they faced the problem of Raptor 1 overclocking, making it possible to lift this rocket at all.

Just a side note

https://3dnews-ru.translate.goog/1026699/glavniy-ingener-raketnih-dvigateley-spacex-pokinul-kompaniyu-ilona-maska?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=ru

 

Not proportionately shorter, ACTUALLY shorter.

The booster was always planned to have the load path from the outer ring of engines go straight up into the the structure of the tank, rather than rely on the puck to distribute the forces. This means that the engines were always going to stick out. This was never a flaw. Aeroshells are simple.

The "engine melting" is not a problem of clustering. Regenerative cooling means that the outside of the engines is downright frosty while in operation. It's a problem of the INSIDE of the engine not  being evenly heated, so despite being evenly cooled, some copper starts boiling off before the theroetical maximum performance (just shy of "the entire copper lining boils at once") is reached.

 

Also, the date on your article is 2 years old. Not news.

[kerbiloid]

3 minutes ago, Rakaydos said:

Not proportionately shorter, ACTUALLY shorter.

V = pi D² h / 4

[Rakaydos]

Just now, kerbiloid said:

V = pi D² h / 4

That's what I said. H has to actually go down, not just go up slower than D.

[kerbiloid]

53 minutes ago, Rakaydos said:

That's what I said. H has to actually go down, not just go up slower than D.

d ~10%

[Rakaydos]

Approxmately ten percent of what? Vomiting math terms on screen doesnt defend your position.

[Kartoffelkuchen]

I certainly believe SpaceX engineers have a rough understanding of what they are doing, know the effects of bolting engines straight to the skirt of Starship, know what impact cutouts in stiffener rings have on strength of their structures, and while it is entertaining to read these discussions, I think certain users here are more interested in making their senseless points over and over again instead of actually supporting an open discussion and maintaining an interesting debate, some arguments might better be ignored from now on.

Edited February 13, 2022 by Kartoffelkuchen

[JoeSchmuckatelli]

Nothing new - but where it's written reaches a more influential audience;

Quote

 

NASA officials — and their longtime aerospace contractors — are watching with a mix of awe and horror

... 

The potty-mouthed D.C. lobbyist, a longtime detractor of SpaceX, described the reaction among his clients to Musk’s presentation on Thursday as “promises, promises, promises.”

But he said such dismissals are passé. “It’s like you keep saying ‘he can’t do it’ but it keeps working. It keeps working. I think people are scared. He’s starting to make people who were never believers think he might.”

 

https://www.politico.com/news/2022/02/12/elon-musk-space-freaking-out-competitors-00008441

 

Edited February 13, 2022 by JoeSchmuckatelli

[tater]

SpaceX has always had detractors, and Musk has always been excited by what SpaceX is doing, and pushes seemingly insane, "aspirational" time lines on projects. In the end all that matters is does it work. Landing boosters wasn't going to work, then it did. "But it won't save them any money until they reuse it at least X times!", then SpaceX says, yeah, it requires a few reuses to break even, but that number is X/3 or X/4, not X, etc.

Starship winning HLS was honestly shocking to me. I always assumed the only way SpaceX sells SS is for it to exist operationally first. I think they sort of thought that way, too. Build it, then people will use it. Years ago, a friend who wrote for ars was keeping me up to speed on space stuff. He was a big BO fan, and since BO is so secretive, he would say things like when people went back to the Moon they'd probably land and find Bezos has already set up Amazon there to supply them. SpaceX is not secretive, but they are sort of doing what people thought Bezos was going to do.

Bezos always says that for amazon he had a head start—he didn't need to invent the post office, internet, or credit cards. All those infrastructure elements meant he could make amazon, minus any, he'd have to invent those first. He'll rightly segue to space by saying that we need a cost effective way to get to space for using space to become something that is actually possible. He is right about both. SpaceX is actually working rapidly towards this future, hopefully BO gets their act together, I want to see 2 companies doing this.

Edited February 13, 2022 by tater

[Beccab]

 

So it begins 

[tater]

[sevenperforce]

21 minutes ago, tater said:

A private company will never be able to put a liquid-fueled rocket into orbit.

Well, a private company will never be able to launch a payload to space and recover it.

Well, a private company will never be able to send a capsule to dock with the international space station.

Well, orbital rocket first stages will never be recoverable.

Well, orbital rocket first stages will never be reusable.

Well, orbital rocket first stages will never be economically reusable.

Well, no private company will ever be able to build a full-flow staged combustion engine.

Well, even a privately-developed full-flow staged combustion engine will never surpass the chamber pressure of the RD-180.

Well, they won't actually be able to fly a vehicle with a full-flow staged combustion engine.

Well, they won't be able to design a vehicle that's able to be aerodynamically stable with the engine off.

Well, they won't be able to transition between aerodynamically stable flight and a powered landing.

Well, they won't be able to fire all six engines at once without breaking everything.

Well, they won't be able to build an orbital launch site at Boca Chica.

Well, they won't be able to build a tower with robot arms.

Well, the robot arms won't be able to pick up the rockets.

----

I'm beginning to detect a pattern.

 

[StrandedonEarth]

2 minutes ago, sevenperforce said:

A private company will never be able to put a liquid-fueled rocket into orbit.

Well, a private company will never be able to launch a payload to space and recover it.

Well, a private company will never be able to send a capsule to dock with the international space station.

Well, orbital rocket first stages will never be recoverable.

Well, orbital rocket first stages will never be reusable.

Well, orbital rocket first stages will never be economically reusable.

Well, no private company will ever be able to build a full-flow staged combustion engine.

Well, even a privately-developed full-flow staged combustion engine will never surpass the chamber pressure of the RD-180.

Well, they won't actually be able to fly a vehicle with a full-flow staged combustion engine.

Well, they won't be able to design a vehicle that's able to be aerodynamically stable with the engine off.

Well, they won't be able to transition between aerodynamically stable flight and a powered landing.

Well, they won't be able to fire all six engines at once without breaking everything.

Well, they won't be able to build an orbital launch site at Boca Chica.

Well, they won't be able to build a tower with robot arms.

Well, the robot arms won't be able to pick up the rockets.

----

I'm beginning to detect a pattern.

 

Would someone please tell Musk that he can't create a ship that travels faster than light?

[Spacescifi]

30 minutes ago, sevenperforce said:

A private company will never be able to put a liquid-fueled rocket into orbit.

Well, a private company will never be able to launch a payload to space and recover it.

Well, a private company will never be able to send a capsule to dock with the international space station.

Well, orbital rocket first stages will never be recoverable.

Well, orbital rocket first stages will never be reusable.

Well, orbital rocket first stages will never be economically reusable.

Well, no private company will ever be able to build a full-flow staged combustion engine.

Well, even a privately-developed full-flow staged combustion engine will never surpass the chamber pressure of the RD-180.

Well, they won't actually be able to fly a vehicle with a full-flow staged combustion engine.

Well, they won't be able to design a vehicle that's able to be aerodynamically stable with the engine off.

Well, they won't be able to transition between aerodynamically stable flight and a powered landing.

Well, they won't be able to fire all six engines at once without breaking everything.

Well, they won't be able to build an orbital launch site at Boca Chica.

Well, they won't be able to build a tower with robot arms.

Well, the robot arms won't be able to pick up the rockets.

----

I'm beginning to detect a pattern.

 

That is the glory of physical laws... they do not care about breaking any manmade status quo. Only that you meet whatever requirements that physical laws require.

If so it won't matter who you are... so long you you have what it takes physics will work for you rather than against you... just like time.

Edited February 13, 2022 by Spacescifi

[Nothalogh]

53 minutes ago, Spacescifi said:

That is the glory of physical laws... they do not care about breaking any manmade status quo. Only that you meet whatever requirements that physical laws require.

If so it won't matter who you are... so long you you have what it takes physics will work for you rather than against you... just like time.

Not entirely true, there is also the political dimension of any project, but that can be dealt with by bringing to bear a sufficient amount of shame and bullying.

[Spacescifi]

5 minutes ago, Nothalogh said:

Not entirely true, there is also the political dimension of any project, but that can be dealt with by bringing to bear a sufficient amount of shame and bullying.

 

Politics is a human construct physical laws could care less about.... even though it is a wall that must be climbed over nonetheless.

[StrandedonEarth]

9 minutes ago, Nothalogh said:

Not entirely true, there is also the political dimension of any project, but that can be dealt with by bringing to bear a sufficient amount of shame and bullying.

Don't forget money. Dump trucks full of money usually work too.

[Nothalogh]

6 minutes ago, Spacescifi said:

 

Politics is a human construct physical laws could care less about.... even though it is a wall that must be climbed over nonetheless.

Aye, but we're kind of stuck with the humans and their constructs.
So that may as well be a law on par with that of physics.

[Spacescifi]

21 minutes ago, Nothalogh said:

Aye, but we're kind of stuck with the humans and their constructs.
So that may as well be a law on par with that of physics.

 

Yes.... scifi can change that though.

[Nothalogh]

11 minutes ago, Spacescifi said:

scifi can change that though.

By exterminating humans?

[tater]

I'll be so happy when they light this candle if for no other reason than it stops the nonsense recurring in the other thread—to be replaced with some other nonsense, but at least novel nonsense is novel.

[Beccab]

Just now, tater said:

I'll be so happy when they light this candle if for no other reason than it stops the nonsense recurring in the other thread—to be replaced with some other nonsense, but at least novel nonsense is novel.

"The payload capacity is actually 2 tons since today I wore blue socks and =~10%"