The article argues that lasers are cheap because you can just run them off a diesel generator in a container. But then it switches to space... which obviously doesn't do well with diesel and refueling.
I assume we're talking about either battery+solar cell or nuclear power on those satellites?
The important part is that their overall energy consumption is low. And their usage is quite bursty so I think you're right that a space based laser would just spend days charging batteries via solar or from an RTG.
Also even on land with the diesel generator, I assume the generator is charging up batteries or super capacitors and not hooked up directly to the laser. Estimating a ~30 second laser discharge, only the most gigantic diesel generators can convert a gallon of diesel to electricity in half a minute.
> And their usage is quite bursty so I think you're right that a space based laser would just spend days charging
Sure, but surely there will be a maximum total power storage that a satellite will have, and if that totals, say, 50 missile zaps, them don't you have the same problem that the enemy could send 51?
When 51 missiles are on their way, you don't have time to recharge from the sun.
And unlike the diesel generator you can't quickly add more power storage the week before when you see what the enemy is about to do.
> And their usage is quite bursty so I think you're right that a space based laser would just spend days charging batteries via solar or from an RTG.
That's not how it would be in a war. Their usage would be exactly zero, and then basically continuous. Not bursty at all - more like off, and then full on.
Energy for the space weapon would be a large problem.
> only the most gigantic diesel generators can convert a gallon of diesel to electricity in half a minute.
That's what they use - the generator is the size of an 18 wheeler.
> That's not how it would be in a war. Their usage would be exactly zero, and then basically continuous. Not bursty at all - more like off, and then full on.
IDK, I see it quite likely that even close to single-shot capability would be good enough. For the kind of a war where you need defence from ICBMs or hypersonic missiles, the active phase of that war has always been expected to last something like half an hour, as both sides launch all the missiles due to the 'use-it-or-lose-it' mechanic where your launch platforms expect to be destroyed by incoming fire and have to spend all their munitions before enemy missiles arrive; and the active phase of a missile defence is even shorter - a few minutes, as most of the arsenal would be launched in a single wave to overwhelm any defences.
So if a satellite needs a month of charging to top up its batteries after some test firing, that's as good as if it needed just an hour; it should be optimized for peak performance of a single relatively short burst of shots, and one with a very fast reaction time - you don't get five minutes of warning to start and spin up a huge generator.
Yup. The article says each laser hit only cost a dollar of gasoline. And obviously electric vehicle batteries are carrying the equivalent of many dollars' worth of gasoline at a time, and battery discharge is fast since all the cells are in parallel. EV batteries bring your car from 0 to 60 faster than your average gas engine, and fast charging transfers energy very quickly.
Almost certainly solar. The limitation isn't so much gathering the energy as it is keeping the thing from melting itself down. If you want to fire it more often you're probably going to have to put a bunch of these in orbit and maintain them indefinitely. Very expensive.
I assume we're talking about either battery+solar cell or nuclear power on those satellites?