politics

Remember it takes about a lot of energy to land something coming down from orbit, that means more fuel, more fuel means more weight. And sometimes it better to put that fuel and weight into putting more shit into orbit.

…That sounds like bull, and quick back-of-the-envelope arithmetic shows there's probably no way it's true in the general sense.

Falcon 9 LEO payload, expended: 22.8t
Payload, recovered: 17.4t
Structural material: Various aero-grade aluminium alloys.
First stage dry mass: 25.6t
Propellant mass (LOX+RP-1): 395.7t
Second stage dry mass: 3.9t
Propellant mass: 92.67t

CO₂ emissions to produce aluminium: 2t·CO₂/t·Al to 20+t·CO₂/t·Al
(Depending on whether fossil fuels are used— Al is very energy-intensive. MINIMUM. Does not include mining, alumina, alloying, machining, etc.)

CO₂ emissions to burn LOX+RP-1: ~0.8t·CO₂/t·Fuel

The launch kinematics shouldn't change too much otherwise, so assume the difference in payload approximately correlates to the fuel amount that must be saved— Oversimplifying and overly linear, I know. (I'm not breaking out Tsiolkovsky for this. You do it, if you want.):

(25.6t * (2t/t)) / ((22.8t - 17.4t) * (0.8t/t))

In even the most conservative scenario, the carbon footprint of the extra fuel to land a Falcon 9 will be somewhere in the neighbourhood of 12X less than even just the raw material costs to replace the aluminium in it.

If we assume a more typical US aluminium production process for a US company, resulting in 11t·CO₂/t·A instead of 2t·CO₂/t·A:

(25.6t * (11t/t)) / ((22.8t - 17.4t) * (0.8t/t))

…Then we're looking at the carbon footprint of the fuel to reuse a rocket being 65X lower the carbon footprint of replacing it. This is still not even counting either the actual mining, preprocessing, and alloying of the aluminium ore nor the machining nor the rocket structure, so the real number will be even higher.

…In fact, it looks like nearly half of all the carbon emissions from a rocket launch are likely to come from just manufacturing the rocket, not even the fuel it burns. I'm honestly pretty surprised by this too; You'd think, and I've always personally assumed, that the big tank of carbon-based fuel and not the thin sheet of metal around it would release the most CO₂, but apparently not.

((25.6t + 3.9t) * (11t/t)) / ((395.7t + 92.67t) * (0.8t/t))

I guess it makes sense when you remember that GHG costs for other types of vehicles are usually amortized over the useful lifespan of the vehicle in question.

Reusable rockets are just kinda inefficient for a lot of shit.

Remember it takes about a lot of energy to land something coming down from orbit,

This entire premise is somewhere between false and dishonest or misinformed. It costs basically zero energy to land something coming down from orbit, compared to what you've already spent to send it up there in the first place, because all you have to do is lower your periapsis into the atmosphere and then fire a quick thrust burst for a couple seconds to land at the end once air drag has done all the hard work of bringing you down from hypersonic to subsonic terminal velocity. The Saturn V had to be millions of tonnes to get to the Moon, but the command module and capsule to get back was kinematically basically one step above an inert rock with a couple of whoopee cushions strapped to the back.

Call out the shitty labour practices, security risks, and deeply problematic political and economic injustices. But don't try to lie about physics.

A Lofstrom loop or a skyhook would be cheaper and safer, honestly