Early Access / Feedback Time!

Looks good Tim, I know I'm late, life happens. I'm paying more attention to SpaceX getting the Dragon off the ground this month. As far is this stainless steel to composite argument, the video tells the tale, trade-offs vs. the cost savings seem well worth it. Can't wait to see the Starship Hopper do its thing.

Yep, I wonder if it is similar to introducing oxygen to a torch, the flame gets hotter because oxygen allows other gases to react, they can't burn without oxygen at any temperature. Altho it's not exactly a "flame" on re-entry, not sure how all that relates to plasma. I do think in the case of plasma you want the gas with the highest thermal expansion, since it isn't reacting, and expanding will create a larger buffer, I think the hydrogen in the Methane would help that expansion. (Disclaimer: Not a chemist, just intrested)

Brant Wedel

The Tim, great video as always. One question I had was regarding which series of Stainless Steel SpaceX is using. I thought it was 304 and not 301. I think Elon tweeted 301 at first, but then corrected himself that 304 was the material of choice. I’ll try to search through past tweets and see if I can’t find definitely if it’s 301 or 304...

Love the updated intro! Hey Tim why use methane for cooling rather than oxygen? As I understand it the speed at re-entry is so intense the gas is virtually a plasma buffer that creates a cooling effect between the shockwave and the surface. So why use methane? Oxygen could not only replenish the ozone but is smells way better!

Thanks for doing your homework and making a complex subject understandable and entertaining.

BO, Spacex and Electron are all in different classes so comparing them is like comparing a car to a motorbike. And each company has very different goals: Spacex has mars+ Earth to Earth Starship transportation, BO has space tourism in mind and Electron is trying to make the small launch market more affordable.

Awesome video as always. Adding the heat testing video that Elon posted would be cool as others have pointed out.

Great video. Not worth changing the video, but the double layer skin (around 11:25) instead of a backbone might be compared to the exoskeleton of a beetle or ant. And we know how much *they* can carry for their size (yeah, because of cube/square law, not exoskeleton).

Paul Black

Oooo good question. Or is that only a titanium thing? (I don’t know enough about metals haha)

Everyday Astronaut

Yes that’s only doable with stainless steel, I hope I made that point clear as it’s melting point is much much higher

Everyday Astronaut

Oh crap... yeah that was a decent clip! Not sure if it’s worth the re render / reupload though. Dang it

Everyday Astronaut

Hmmmm that I don’t know for sure but there won’t be any soot from the engines since methane burns clean but yeah it could get scorchy but I don’t know enough to say for sure

Everyday Astronaut

That was mostly meant to set the tone that it’s perfectly fine if the payload capacity does go down, not necessarily thinking it will ( I even said I don’t think it will)

Everyday Astronaut

Unfortunately that number is all over the place, just too many variables and too many round numbers to illustrate accurately. The cryo and room temp we can do accurately but metal failures at high temp is really hard to nail down

Everyday Astronaut

Well done! Love seeing the development of Starship... I wonder if the stainless steel will have the bluing affect from being tempered due to re-entry heat...

Great video. Was the heatsheild issue ever solved with carbon fibre? I remember hearing about various materials (PICA-X?), but some seemed to be ablative. Is the "sweaty spaceship" solution only in fact possible/applicable with stainless steel? If so, that's another advantage over carbon fibre.

maybe add heatshield flamethrower test video?

Don’t change anything. Great job!!

Great video Tim. I didn't get the answer only to a question: will reflecting of the shield degrade during reentry while the shield starts to become darker from burning through the atmosphere? I know it will not be a Engine-First reentry, but still Shuttle did not look shiny after reentry.

Great vid, only wish you had more insider knowledge to know the details for sure :-) Still, really enjoyed it and hope you continue to be able to explain why and how these rocket companies use materials. Perhaps a comparison between SpaceX, Blue Origin and Electron (or more) to help us understand the differences, pros and cons, of each approach? Fab matey :-)

A good piece. The only quip I have is with your speculation at the end of the video, regarding the payload to LEO. Musk has hinted that Raptor will be getting a thrust improvement. How much, we don't know, but that might also compensate for the whole stack being heavier than originally planned.

Thank you Tim for the great video. A question is left for me: wasn't it a special stainless steel with more oxygen atoms or so? I thought it wasn't the same material a for cooking. Best wishes from Germany

Any links to the research you looked at? I’m interested in learning more about these things myself.

Very informative and enjoyable presentation. Be well.

Great job Tim! One thing you may wish to include is a chart showing the strength versus weight at ambient, cryogenic and re-entry temperatures. That may illustrate the advantage of stainless 300 even further. I suppose the third bar would require different units, as it really wouldn't be expressing the same thing, but having them all together would look cool and informative.

Failed on the transition? Can you provide a little more feedback? I don't see anything wrong.

Everyday Astronaut

You failed on the first transition after the title

Great new titles, and well researched!

Big Car