Comment by dpark
7 days ago
Why would launch costs be low? $10/kg is fantasy land. UPS won’t ship a kilogram across the country for $10.
And who wants spent nuclear fuel in low earth orbit? This is a far worse location for spent fuel than buried in a bunker. This is a worse location than Times Square.
> UPS won’t ship a kilogram across the country for $10.
I can purchase produce grown on a different continent for less than that at the grocery store so something isn't right here.
It was a metaphor for how absurd the statement was. But if you try to ship a 1kg package across the country it will likely cost way more than $10.
Freight cost is certainly way lower.
Why wouldn't they be low? In the limit, if launch becomes operationally similar to air travel, costs will be a few times propellant cost. And propellant is very cheap. LOX is almost free (the second cheapest industrial liquid after water) and liquid methane isn't very expensive either.
Low earth orbit would just be where it's transferred to something to carry it farther out, for example using solar-electric engines.
For all this, remember it isn't done immediately, it's done in (say) 300 years when the short lived fission products are mostly gone.
I think the onus is on you to explain why costs would drop by >3 orders of magnitude (>4 accounting for the 10x launch armor). It’s something like $1500/lb on a fully loaded Falcon Heavy and all indications are that SpaceX isn’t making money at that price.
Plus even if this were free, “shoot 180k tons of nuclear waste into space” seems like a terrible idea in general. It’s one of those ideas that make sense only until you think about the ramifications. What happens when inevitably one of the 3 thousand Falcon heavy rockets explodes and the armor fails and we spread nuclear waste over 3 states?
Falcon Heavy is more expensive per kg than F9, because it throws away more things. SpaceX flies it for certain military missions but you will note they launch their own stuff on F9.
A full launch on F9 (with recovered S1) is estimated to cost $15M and can put up to 17,600 kg into LEO, or $850/kg.
> (>4 accounting for the 10x launch armor).
You're double counting there. 3x would be just fine even with 10x launch armor.
> seems like a terrible idea in general
And here's the problem: you started from an emotional reaction and are trying to rationalize that.
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$10/kg isn’t fantasy land if we have fusion rockets, but then we don’t need fission power anymore. :)
Fusion would be useless for launch to orbit. Even fission sucks for that. It's really hard to beat the cost and power density of chemical rockets.
Depends. If we get explosive inertial confinement fusion to work you could build a pure fusion version of a nuclear pulse rocket. Look up Project Orion.
Orion (in its fission bomb form) is impractical and would be insane to launch from Earth, but it holds the title of being the only “torch ship” drive we know how to build. We could technically build it.