First of all, not sure how I missed that batshittery post from a while back. Love it. That Sprint's gotta home in on an attitude reading immediately upon exiting the ground because of the nutzo acceleration as the engine turns on. Your best bet is pointing it as straight towards the final heading as you can before it gets going, or else it's going to lose control, or at the very least waste a lot of fuel. Very impressive tech for that era.

Though the atmosphere may shield you from radiation before e.g. Trump's radioactive hurricane arrives, the problem with ground-based defense systems is the atmosphere. The thing that ablated and destroyed Sprint missiles. If I were to keep one national secret as secret as secretably possible, it would be a relatively robust space-based missile defense system. It could be fairly easily miniaturizable; a satellite constellation in polar LEO orbit would provide an initially large velocity for any launched missiles, and the lack of atmosphere throughout the trajectory would require much, much less fuel.

I dunno, even if the Iridium constellation was secretly packing ten micro-missile interceptors in each satellite (lol it's not), that'd still only be about 750 intercept chances. It's like 90 min./orbit in LEO, so the logistics are daunting if Russia launched a whole buncha ICBMs quickly. Honestly, I don't think that the public-facing technology (I know of) for microsat-scale (and especially cubesat-scale) stuff is advanced enough to indicate it possibly being driven by a secret and sizeable gov't program(s). Car-sized satellite systems seem to be where it's still at. And those're harder to hide, obviously, but surely Russia has similar tracking capabilities vs. US, which should extend to resolving satellites of sizes down to < 10 cm -ish. So cubesats.

You're right though, public domain says we do only have a li'l defense thang. Sounds like it deserves nothing more than such verbiage.

Maybe we could just not do nukes.? Everywhere?

chanting DE-VALUE PHYSICISTS! (repeat)