Brilliant Pebbles was a system intended to keep thousands of missiles in orbit over the Soviet Union ready to destroy ICBMs as they launch.
I'm skeptical of this article, but it claims that this could be done fairly cheaply today.
https://sergey.substack.com/p/marbles
Of course, a system like Brilliant Pebbles is most useful when it is publicly known. So will any country be publicly known to have a system similar to Brilliant Pebbles by 2040? Due to the somewhat subjective nature of this question, I will not bet in this market.
@EvanDaniel The local version of Brilliant Pebbles (GPALS) seemed to require ~1000, so that seems like a good benchmark.
@SemioticRivalry Seems sensible. I'm just curious whether "the demo system is operational, 6 vehicles are in orbit, and we intercepted one target out of three live fire tests" would resolve as YES, or whether you're looking for something more fully operational.
@EvanDaniel I wouldn't count that, I think it'd have to be a nation-state credibly announcing that they have operational defense systems along the lines of Brilliant Pebbles as a warning to other nuclear states, that at least a medium-sized exchange has a low likelihood of getting through. I don't think it should need to defeat all of Russia's 500 ICBMs with a 100% success rate, but it should have a good chance of stopping a North Korean launch.
@SemioticRivalry Makes sense. Note that you need a bunch of them just to reliably defeat a single launch -- a single vehicle only has a range of hundreds to a few thousand km depending on when you're trying to make the intercept, and you need a vehicle close to the trajectory at time of launch. I think the "local" estimate of 1000 seems a bit low, but not egregiously so; I haven't checked the math. That seems like a perfectly reasonable cutoff for "probably at least somewhat operational".
This is a proposal to build a fleet of high performance rockets. The cost model literally doesn't have a line item for the rockets. The entire propulsion system -- almost certainly more than half the mass -- is "etc.":
don’t have the exact specs, but my best guess is that a Brilliant Pebble could cost on the order of magnitude of $20,000 today - $10,000 launch cost, $3,000 sensors, $1,000 compute, $1,000 solar panels/batteries, etc.
This is simply an absurd take.
Could it be done? Could it be done cheaper than traditional defense industry approaches? Does increased volume help reduce unit cost? Of course! But if you're not worrying about the design, manufacturing, and test of this propulsion system (especially, but not only, the engines) from day 1, you don't understand the problem.
(For context, I'm a manufacturing engineer who works on rocket engines not entirely unlike the ones this system would need.)
@EvanDaniel Thank you for the info! This is why I love manifold. I can put up a market and have a rocket engineer come in and tell my why it's bullshit