News Changes to the SpaceX BFR rocket.

[Thunder Chicken]

Planned is at the end of October, the last V2 launch. Of course, plans change....

Oh no...not V2s!!! We care where these land!

 

[Urwumpe]

Oh no...not V2s!!! We care where these land!

Well, thats not my department.

 

[GLS]

Well, thats not my department.

 

[GLS]

https://twitter.com/x/status/1964758113422299415

 

[GLS]

https://twitter.com/x/status/1965490867512516924

 

[Urwumpe]

Sounds like they repeat the lessons learned from the R&D process of the Space Shuttle now.

 

[jedidia]

Sounds like they repeat the lessons learned from the R&D process of the Space Shuttle now.

"Well, after all, you couldn't trust those! Those were made by the government! Since we're much smarter than the government, it was perfectly reasonable to assume that we could get away with it!"

 

[GLS]

Another one coming up

https://twitter.com/x/status/1968380376684052830

 

[GLS]

https://twitter.com/x/status/1970282201360277729

 

[RisingFury]

• Initially Musk claimed the reason for steel outer skin was because it doesn't need a heat shield. Turns out it does.
• An ablative heat shield might be easier to apply to the ship, but obviously would need to be rebuilt for each flight. So instead, let's go for a complicated tiling system.
• They're making the ship reusable. What the fucking hell for? There's no real market for a rocket this size. A moon or Mars program would not launch 1000 rockets.
• To make the ship reusable, they've traded heavy wings for extra fuel and fins. Except the landing now relies on the engines working and pulling off a complicated maneuver instead of semi-gliding down.

Happy-go-lucky iterative design

 

[diogom]

• Initially Musk claimed the reason for steel outer skin was because it doesn't need a heat shield. Turns out it does.

Come on, do better than just making shit up. 1:50:

https://twitter.com/x/status/1792652348348620859

To make the ship reusable, they've traded heavy wings for extra fuel and fins. Except the landing now relies on the engines working and pulling off a complicated maneuver instead of semi-gliding down.

Yes, and? This has been a design thing from when it was a carbon fibre render, and so has returning to the launch tower, not a product of the past 5 years. How does a gliding, unpowered descent work here?

 

[jedidia]

Initially Musk claimed the reason for steel outer skin was because it doesn't need a heat shield.

I've never heard that. Not saying it's impossible he said something like this, but it would be fairly obvious that it's BS. Even if it could take it, you heat steel up like that, you don't have the same kind of steel anymore afterwards, I think Musk would have been aware of that.

 

[Thunder Chicken]

I've never heard that. Not saying it's impossible he said something like this, but it would be fairly obvious that it's BS. Even if it could take it, you heat steel up like that, you don't have the same kind of steel anymore afterwards, I think Musk would have been aware of that.

We also need to remember that the fantasy that Musk has been chasing is interplanetary missions to Mars with a thin atmosphere and the Moon with no atmosphere. Until they can get out of our gravity well they are going to have to cope with our thick and chunky oxidizing atmosphere. The stainless steel IS really tough stuff, and it certainly can handle greatly elevated temperatures as compared to aluminum alloys like in the shuttles. It very much needs a TPS, but not nearly as much as a shuttle as it can tolerate higher interior side temperatures without structural consequence, though thermal protection of internal systems, crew, and cargo is another matter.

 

[GLS]

thermal protection of internal systems, crew, and cargo is another matter

Just make all those out of stainless steel...

 

[Urwumpe]

In theory, you could build a reentry vessel out of stainless steel. But, you would need to use large curve radii to prevent nasty hot spots and a very low mass to density ratio.

A real spacecraft would likely NEVER allow that, with all the other engineering requirements.

 

[Thunder Chicken]

Just make all those out of stainless steel...

Could just use Starship to deliver stainless steel to Mars and call re-entry the self-smelting feature.

In theory, you could build a reentry vessel out of stainless steel. But, you would need to use large curve radii to prevent nasty hot spots and a very low mass to density ratio.

Well, when most of the cryogenic propellants boil away on the way to Mars, it might have a very low density indeed.

 

[RisingFury]

Come on, do better than just making shit up. 1:50:

https://twitter.com/x/status/1792652348348620859

Yea, this is the 2019 clip with "heat shield can be much lighter", when reality started setting in. Before that, he claimed that stainless steel, cooled by fuel would be a viable heat shield and before that, he claimed the stainless steel would simply take the heat.

In theory, you could build a reentry vessel out of stainless steel. But, you would need to use large curve radii to prevent nasty hot spots and a very low mass to density ratio.

A real spacecraft would likely NEVER allow that, with all the other engineering requirements.

As a recent test of an inflatable heat shield showed, yes, I'm sure you could build a bunch of interesting designs.

 

[GLS]

https://twitter.com/x/status/1972798064403357887

The eleventh flight test of Starship is preparing to launch as soon as Monday, October 13. The launch window will open at 6:15 p.m. CT.

 

[GLS]

https://twitter.com/x/status/1976058665280078003

 

[GLS]

https://twitter.com/x/status/1977437926041825737

https://twitter.com/x/status/1977484495482695913