Rakaydos

Given that the intermediate zone is RUD territory, and that rocket engines are incredibly optimized, I doubt an off the shelf engine could cover both regimes. Certainty not without including the same exotic materials from the OR turbopump in the main combustion chamber and nozzle!

First things first- if you perfectly mix the fuel and oxidiser, combustion will be too complete and you'll melt any material in existance. They have to be off-balance to have enough unburnt cool propellant to keep the temperature to reasonable levels, for rocket science levels of reasonable. Second- metals that dont combust in hot oxygen rich enviroments are difficult. So it's normally easier to run the exhausts fuel rich, and also offers better ISP with most fuels that are lighter than their oxidiser.

Not ORSC. FFSC, but on the oxygen rich side of schtochimetric. Higher thrust, lower ISP, cheaper and denser propellant mix.

The majority view on NSF is that The Engine to Surpass Raptor is probably a second-generation FFSC methalox engine, using all the lessons and materials developed for Raptor 2 but unrestricted by Raptor's form factor, which was locked in years ago. Particularly optimizing "thrust per dollar" with the goal to make it so the cost to travel to mars is within the reach of at least a million people who want to go. Also some speculation of Oxygen-rich methalox mixtures.

"Raptor 2 has siginificant improvements in every way, but a complete design overhaul is necessary for the engile that ACTUALLY makes "life multiplanetary"" Raptor 2 still exists, it just wont be eneough to make life multiplanetary. We already knew "raptor wont be really ready until, like Raptor v5", so it looks like "Raptor v5" is going to be this new engine. https://twitter.com/elonmusk/status/1413909599711907845?s=20

Raptor 3 wont be Raptor anymore, but Raptor 2 will still exist.

They've already hit on the "part reduction" of making the Upper Stage, Mars transit craft, and earth return vehical the same structure. Any optimization of the engine is going to have to work for all three regimes. Put me down for "One of our interns came up with a cool idea that'll probably be cheaper, but means throwing out everything we've been doing with Raptor." They'll indulge sunk costs for Raptor 2, get the production line running for Raptor 2, and then the engine team will dive into this other idea.

Ocean acidification

The problem with the "kilometer of ice" arguments isnt the freezing temperature, but the evaporation temperature. Steam is ALSO a greenhouse gas, and the higher the global temperature average, the number of places with water that get significant evaporation also rises. (this is not, strictly speaking, "boiling the seas," but the closer the water gets to boiling temperature, the more likely any given atom might recieve an anomalous spike of energy that leads to that atom turning to steam- which is the process of evaporation) This means that as global temperatures rise, it will take less to KEEP them rising... While simultaneously leading to bigger storms and stronger pressure gradiants, as well as more flooding as rivers and coast experience more water than mere "sea level rise" would account for. Melting glaciers and sea level rise are the wrong side to be looking at. Evaporation rates is.

Other end. The straight fins are the equivilant of SpaceX's grid fins, the flare at the far end is the engine bay cowling.

I take it that's a no.

So has anyone in this thread been following the climate summit?

So, less "my way or the highway", and more "If you arnt part of the solution, stop being part of the problem."

I'm not sure what you mean?

"The enemy gate is down."

Ironically, China is actually doing more about their CO2 footprint than America is.

This is where the ~20 year lag time is lethal- we have to act 5 presidential administrations before a crisis to have any hope of heading it off. And it's looking like the world is having a hard time meeting that kind of challange.

Life adapts when change happens over thousands of years. Not so much, when it happens over mere decades.

You still havnt addressed the existing strengthened storms. A model is considered useful when it reflects what is actually happening.

Welcome to chaotic systems. If it were easy to model, the weather man would never be wrong. But the changes in hurricane strength is well documented at this point.

Independant factors. Hurricane strength is rising dramatically just off existing climate change.

Average sea level, in this case, matter less than storm surge and hurricane count and strength. The global average sea level might only be rising a few MM per decade off ice melt, but a hurricane can locally raise the sea level meters at a time, with waves on top of that.

Slow is relative. A major city like, say, miami has about half a million people. Just building half a million new apartments, somewhere out of the flood zone, is going to be tens or hundreds of billions of dollars- and that doesnt even count infrastructure, like sewer mains, power lines and internet connections, or services, like schools, commercial districts, and office space, if you build it a place not already choked with existing construction. That's not the sort of thing that can appear overnight. Having to abandon all the existing infrastructiure we built in what is now the "wrong" places is what makes things difficult.

That's a MERV. (multiple independant reentry vehicals), which the person disallowed. How much did the Tsar bomba mass? that might be more of a restriction, though the weight might be difficult to find when explosions are measured in the equivilant weight of TNT. Edit: 27 tons, so an expendable could carry 9 50-megaton bombs. I probably slipped a digit in my previous post.

For this thread, we dont care about practical reality, so lets pull out the big numbers. "Even more efficient than fission, nuclear fusion would liberate 6.46 × 1014 Joules of energy per kilogram of hydrogen fuel, meaning it would take a mere 867 tonnes of hydrogen to power the world" "TNT has an energy density of 4.6 million J/kg. This means that setting off one kilo of TNT releases 4.6 million Joules of energy," ...running some numbers... "Sir, we estimate that starship could carry a 140 megaton Fusion Bomb, almost 6 times more powerful than the largest nuclear bomb ever deployed." wait, that's the reusable numbers. 250 tons expendable... call it 225 megaton thermonuclear weapon. 9 times larger... so round up an call it an "Order of magnitude improvement."