SpaceX Super Heavy and Starship updates

[DocM]

2 hours ago, Draggendrop said:

>

Dump the up mass for now...fly and iterate as you go...NASA is not involved...they can do what they want, when they want.

>

 

Upmass may not change that much.

 

It's possible  an all-in-one metal hull may be of similar mass or lighter than the combination of composite tanks +  LOX tanks Invar lining + metallic TPS + its mounting hardware. 

 

Extra points for reduced structural complexity & "touch"  hours.

Edited December 9, 2018 by DocM

[RGClark]

On 12/9/2018 at 3:23 AM, DocM said:

 

Upmass may not change that much.

 

It's possible  an all-in-one metal hull may be of similar mass or lighter than the combination of composite tanks +  LOX tanks Invar lining + metallic TPS + its mounting hardware. 

 

Extra points for reduced structural complexity & "touch"  hours.

 Yes. 

 Actually some new metal alloys are even better on strength-to-weight than carbon composites. Elon had referred to the change to metals as counter-intuitive. I think this is because the prevailing view was carbon composites had to be used for rockets to save weight. 

 

See discussion here: 

https://exoscientist.blogspot.com/2018/06/darpas-spaceplane-x-33-version-page-2.html 

 

 There are some aluminum, titanium, and steel alloys mentioned. I'm inclined to think it's a titanium or steel alloy as Elon referred to it as "heavy". Titanium or steel would also have the advantage of having better heat resistance. And some of the high strength alloys can be 3D-printed, which is a focus of Elon's.

 

 

  Bob Clark

[Draggendrop Veteran]

Hopefully we will find out soon.

 

The real problem speculating ...is that there are so many alloys available...to solve various particular problems.

 

Everything is a trade off. 

 

For the Starship applications....a few area's have different concerns.

 

It will all boil down to cost, availability, dissimilar expansion joints, high heat properties and tooling...to name a few.

 

100 engineers in 100 area's of expertise can give you 100 different answers...what is SpaceX's priorities as a whole, at the moment.

 

Stay tuned for new info in the new year...a few weeks away.

[DocM]

Many alloys have been mentioned for the Starship's "heavy metal,"  but Musk went out of his way to like and link to an article about high entropy alloys.

[Draggendrop Veteran]

16 minutes ago, DocM said:

Many alloys have been mentioned for the Starship's "heavy metal,"  but Musk went out of his way to like and link to an article about high entropy alloys.

liking an article does not imply that is what they chose.

 

I place a "like" on engineering articles because of the thought and math that went in it...not because I endorse it.

 

I do not remember Elon  mentioning any alloy...period...and everyone online is an "expert of some sort...some warranted , most not"... but until we hear a SpaceX statement...it's all speculation. 

[DocM]

Is it a PR mock-up, a Starship-class Grasshopper testbed with KISS legs, or some undefined thing ....

 

 

👆👆 Note the angled top on the above shiny segment...

 

 

 

[DocM]

Cropped view of a night shot inside the sprung structure shows a nose cone.

 

Credt: bocachicagal

 

So much for clean room assembly... I think we have a Big Falcon Hopper being built in the middle of a Texas marshland, with the main structure being built by Caldwell - a company that builds municipal water tanks.

 

OldSpace guys: "Lord, help us 😵

 

Dogs & Cats, living together! Mass Hysteria!!"

 

 

Edited December 22, 2018 by DocM

[DocM]

 

[DocM]

 

 

[DocM]

MUSK SPEAKS

 

 

 

 

Edited December 23, 2018 by DocM

[Beittil]

Man, that is friggin insane haha. Still wouldn't surprise me if that thing at Boca Chica is just a fancy water tower for the local offices and utilities haha.

[DocM]

The OldSpace guys are gonna have strokes....

 

 

[DocM]

 

 

[DocM]

Their own superalloy fundry, and 12,000 psi (82,737 kPa) hot oxygen? 😵

 

 

Edited December 23, 2018 by DocM

[Blue-Vision]

Okay, yeah. This has to be the SC superalloy we've been hearing about, then. Can't imagine they're gonna use straight-up stainless steel on the final product.

 

- That thermal & tensile strength must be crazy good to withstand 12k+ psi pressure (or more) ... can't wait until specifics are released (if they are released). Wow.

- "Radically redesigned" Raptors, eh? 12k psi on the turbopumps ... yeeesh ... hungry. The Merlins are not quite 3* less pressure, so we can't infer performance based on that alone because it's not linear.

- I wonder if they're going to get good data from the lower weight "testing" version of Starship ... and I'm sure they're aware of that.

 

All "wait and see" stuff, so far.  

[Draggendrop Veteran]

6 hours ago, Unobscured Vision said:

Okay, yeah. This has to be the SC superalloy we've been hearing about, then. Can't imagine they're gonna use straight-up stainless steel on the final product.

 

- That thermal & tensile strength must be crazy good to withstand 12k+ psi pressure (or more) ... can't wait until specifics are released (if they are released). Wow.

- "Radically redesigned" Raptors, eh? 12k psi on the turbopumps ... yeeesh ... hungry. The Merlins are not quite 3* less pressure, so we can't infer performance based on that alone because it's not linear.

- I wonder if they're going to get good data from the lower weight "testing" version of Starship ... and I'm sure they're aware of that.

 

All "wait and see" stuff, so far.  

I don't know where you are getting your info from, but it is mixed up.

 

The superalloy(s) were always for the Raptor with several proprietary solutions in test.

 

The "heavy metal" is for the "ship", and it is stainless 301. SpaceX almost has it's own "foundry" up and running.  Stainless will work just fine with many advantages. You need to do some research on stainless. There is no such thing as "straight up stainless".

 

Seriously...you need to keep up with the "data released" and ask questions if unsure. Posting incorrect data messes everyone up when they are checking this thread for data...and it wastes others time correcting it....some of us don't have the luxury of time.

 

You can do better, I have seen you do much better....just a friendly reminder.

[DocM]

 

[Draggendrop Veteran]

With respect to SX300 and SX500 superalloys for Raptor...still approaching 300 bar...

 

Quote

Our superalloy foundry is now almost fully operational. This allows rapid iteration on Raptor.

https://twitter.com/elonmusk/status/1076686201061404672

 

and 

 

Quote

SpaceX metallurgy team developed SX500 superalloy for 12000 psi, hot oxygen-rich gas. It was hard. Almost any metal turns into a flare in those conditions.

https://twitter.com/elonmusk/status/1076684059827302400

 

and a "redesign" of Raptor...ready for final testing...shortly...

 

There may have been a few extra "efficiency tweaks" and a  "foundry development" to boot.

 

This is a major step in vertical integration for such a complex engine...all in house...excellent move.

 

We need the technical overview ...

 

---------------------------

Then...

Quote

Stainless steel is correct, but different mixture of alloys & new architecture. Unlike Atlas, Starship is buckling stable on launchpad even when unpressurized.

https://twitter.com/elonmusk/status/1076595190658265088

 

and...

 

Quote

While there are some material similarities, Starship is very different from the Atlas design

https://twitter.com/elonmusk/status/1076606482332807168

 

Along with the tweets of the past few weeks...

 

Appears the "hopper will be of "stainless 301"...tough as hoot and easy to fabricate for testing...all the while having an almost endless pool of "TIG" welders around...KISS

 

The Starship for orbital insertion will be a "special alloy version for this stainless iteration....could there be a probable SpaceX  SX(*****) version for their stainless variant being cast in their foundry, but "metal yard" out sourced for sheet ...This is very impressive.

 

Fly and test variants...then inhouse it if costs become silly....not like they haven't done this before.

 

-------------------------------

Elon has stated that after the hopper is "done"...a "technical overview" will be given...That will be one heck of a "Tech Fest" 

 

Meanwhile...

 

 

larger image...

https://i.ibb.co/vYH6Gnh/Expanding-Brain.jpg

posted by NSF user blasphemer...just had to put it here....This is true and hilarious.....

 

-------------------------------------------

This will be a difficult "mind adjustment" for some...but...from my experience, aluminium has always been thought of for aviation and marine applications due to "weight" if you will...stainless variants have brilliant specs...but the "weight" and/or cost always removed it from consideration and mass production.

 

If it is used on a much larger structure and combined with reusability for a particularly demanding regime...costs can be absorbed and mass can be deceptive when considering wall thickness and bracing for large structures...

 

Can't wait for the technical overview...meanwhile, online...some get it,...some prefer not to....their loss, but they get a shiny metallic rocket as consolation.

 

As a side note...for those of us with fab shops...heavy metal has always been considered "stainless", the ideal metal for longevity and toughness...just usually out of range for the hobby shops unless it is real important.When Elon first tweeted it, a few of us on NSF knew what it meant...but only a slight mention was made...because we knew people would go ballistic there...not so anywhere else though...kind of funny with dedicated forums sometimes.

 

Life goes on...waiting for Elon's Technical Presentation forecast for.................spring maybe?

 

// side note...I would bet that the Boring Companies advances may also have had a role to play....crunching rock is not done with light metal...

Edited December 23, 2018 by Draggendrop

[DocM]

Noticed another item; the  structure has an internal lattice, which some questioned as a sign of  flimsiness but ISTM should turn its "balloon tank" into a fairly rigid structure.

 

Stainless steel is also good for laser welding, which makes for easier patching/repairs. 

 

 

Edited December 23, 2018 by DocM

[Blue-Vision]

I'm of the exact opposite mindset. Internal structure adds internal-facing and external-facing strength if done correctly. The math agrees with me also.

[Draggendrop Veteran]

A "skeleton" if you will, or lattice structure will add strength for the intended purpose..as engineered.

 

37 minutes ago, Unobscured Vision said:

/snip/   The math agrees with me also.

You may want to rephrase that...unless you have all the specifications for this unit...and have done all the real world engineering on this structure.

 

You need to be mindful of expressions....you will be called out to prove it. An opinion is another matter that requires no proof.....but can make one look foolish as well.

[Draggendrop Veteran]

1 hour ago, DocM said:

Noticed another item; the  structure has an internal lattice, which some questioned as a sign of  flimsiness but ISTM should turn its "balloon tank" into a fairly rigid structure.

 

Stainless steel is also good for laser welding, which makes for easier patching/repairs. 

/snip

Bit tired today...forgot to mention...

 

Since they are working with "real metal" ( this ought to tick off someone....)..The laser hand held was interesting.

 

The oil and gas industry have automated welding and testing rigs for pressurized pipelines...I am sure SpaceX is more than aware of this and may employ these types of machinery on the production line...don't mind me as I am very biased towards stainless derivatives and have been for a very long time.

 

It is nice to see an opportunity, in this field, to use a material such as a stainless...why launch the missile when we can launch the silo...😎, which, along those lines, was probably said during one of their meetings....and Elon apparently  said...make it so...

[Blue-Vision]

/sigh ... 

[DocM]

 

[Draggendrop Veteran]

4 minutes ago, Unobscured Vision said:

/sigh ... 

If one is going to hope to work in engineering in the future...I am not kidding, this is a reasonable reminder that it is time to buckle down...and if one makes a precise statement, you will get called out on it and labeled...like it or not.

 

I have been in this field for a very long time...it would be wise to listen once in a while.

 

I have rarely heard certified junior engineers express themselves as such...let alone students, the longer you are in engineering, the more you don't know and it is humbling...but gives focus.

 

Always choose words carefully. It reflects on you...and ticks off veterans of the field who have done their time and more...ones who don't take kindly to a perception of arrogance..it will cost you a job.