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Comment by ExoticPearTree | original | SpaceX catches the Starship to end Flight 15
[−]ExoticPearTree · 2026-11-15 Sun 07:22 UTC · link
I was reading in the comments that the rocket itself is made of steel. What if they manage to build it out of a lighter alloy that has the same or better properties when it comes to going and coming back from space?

What if, considering how SpaceX simplified rocket engine design figures out that, i don't know, adding a little bit of ammonia to the mix, makes the engines perform 10% better? Or 15%? Obviously not a rocket expert, but I don't think we (as a species) experimented with all the possible combinations of chemical compounds to get the best possible output to make a rocket get to space.

I us a lot of what IFs, because in the past few years we've made technological jumps that prior to that it would have taken us decades.

Indeed, wild time to be alive.

[−]ballooney · 2026-11-15 Sun 07:48 UTC · link
Read “Ignition!” by John D Clark. The field of chemical propulsion is far more mature than you realise, there are no more basic ‘whatifs’ like your hypotheticals.
[−]Turneyboy · 2026-11-15 Sun 08:28 UTC · link
> I don't think we (as a species) experimented with all the possible combinations of chemical compounds to get the best possible output to make a rocket get to space.

What makes you think that? That's a nice thing to think but mostly comes out of ignorance of the field.

[−]ExoticPearTree · 2026-11-15 Sun 15:42 UTC · link
Because we don't know everything. We find out each day new things about chemistry, the universe and so on.

When it comes to rockets, yes, I have zero knowledge beyond the basic functioning of one. On the other hand, I look at how the Raptor engines were simplified to make them more reliable, with fewer failures and so on. And my gut says they are not yet with enhancing their performance and reliability.

I may not know much about chemistry, but, call me ignorant, I don't think we discovered all the combinations between elements in order to ignite something or make it go boom.

Like with fusion reactors, in theory they work, in practice we haven't figured out how to initiate a reaction and keep it stable "forever".

More progress will come, at a much faster rate than ever before.

[−]ballooney · 2026-11-15 Sun 18:17 UTC · link
Yeah that’s just wrong. For chemical propulsion we no exactly what sort of valence arrangement of electrons and mass of combustion exhaust products is optimal for getting the most acceleration for your reaction rate. It’s mostly because simpler is better (eg if pure hydrogen could be a combustion product it would he impossible to improve on that). More complex molecules will be strictly worse than anything we know about already. As you said yourself, you know nothing abour rockets or chemistry. Read the book everyone has been recommending.
[−]WalterBright · 2026-11-15 Sun 08:53 UTC · link
There's been a lot of experimenting with rocket fuels.

https://www.amazon.com/Ignition-Informal-Propellants-Univers...

[−]pfdietz · 2026-11-15 Sun 14:51 UTC · link
What alloy would that be? Aluminum? Doesn't have the temperature tolerance. Titanium? Nightmarish to manufacture and expensive. Composites? Temperature intolerance and they tried it; not robust.

Stainless steel lets the structure get very hot on entry without failure, beyond the temperature where aluminum alloys would lose substantial strength. This reduces heat shielding requirements.

[−]hparadiz · 2026-11-15 Sun 17:14 UTC · link
The sky is the limit really. The shape and design is sound so now you can test all sorts of options. Internal frames to buttress the structure. Mixed materials. Composites. You name it. Steel is super easy and cheap for prototypes but if you know you can get the ship back you can play with all sorts of variables.