We could. The usual stumbling block is how to ship fissile material upwell without the risk of a launch failure spreading highly radioactive material over several countries.
> What's the power loss from beaming down power?
I think it's about 10% from atmosphere alone, but you have to add losses from other components in the system, including light -> current -> RF and RF -> current legs, and I've seen estimates ranging from 15% to 40% efficiency end to end; this random article includes breakdown with estimates, that multiplies down to 37.5% efficiency end-to-end.
Also to spell out another non-obvious aspect of beamed power, it turns out that it's not the efficiency that's the limiting factor per se, but land - you can improve efficiency by building larger rectennas, but it gets very expensive very quickly once you consider paying for land under them.
> Could we have giant nuclear reactors in space?
We could. The usual stumbling block is how to ship fissile material upwell without the risk of a launch failure spreading highly radioactive material over several countries.
> What's the power loss from beaming down power?
I think it's about 10% from atmosphere alone, but you have to add losses from other components in the system, including light -> current -> RF and RF -> current legs, and I've seen estimates ranging from 15% to 40% efficiency end to end; this random article includes breakdown with estimates, that multiplies down to 37.5% efficiency end-to-end.
https://www.sciencedirect.com/topics/earth-and-planetary-sci...
EDIT:
This system design gives 7-14% end-to-end efficiency: https://arxiv.org/pdf/2206.08373
EDIT2:
Also to spell out another non-obvious aspect of beamed power, it turns out that it's not the efficiency that's the limiting factor per se, but land - you can improve efficiency by building larger rectennas, but it gets very expensive very quickly once you consider paying for land under them.
See:
SNAP-10A
BES-5 (oops, sorry 'bout that Canada!)
TOPAZ-I
Kiwi, Phoebus, and NRX (Mars here we come!)
RD-0410 (Dossvidanya Solar System!)
SP-100
TOPAZ-II
Kilopower