[varenc]

For those curious on how a nuclear-powered missle could work...

On the Pluto project a ramjet scoops up air, and then the decay heat from a radioisotope is used to heat that air and expel it to generate thrust.

The range really is practically unlimited. The Pluto missle could have flown for months. Nuclear fuel just has over 1000x the energy density of fossil fuels (but lots of complexity around using that energy)

Hypersonic re-entry vehicles seem effective at beating missle defense systems, but a nuclear ramjet missle always in the air seems like it'd have other advantages. (First strike? Persistent threat even after all land/water based missle systems are destroyed?)