I think we'll see nuclear propulsion for Starship variants that receive fuel rods in orbit and are not designed for reentry. Interplanetary logistics between Earth/Moon/Mars orbits.
If he really wanted to, he's rich enough to build the enrichment facilities himself. Could hide it underground in one of those tunnels, claiming the power consumption is a cryptocurrency mining rig or an AI server farm.
I suspect at least ten government agencies from various nations all have him/his assets under 24/7 surveillance just to make sure he doesn't do something at least this unwise.
If SpaceX was willing to do the work and put in the investment they could absolutely get access to fissile material. The US government evaluates things based on regulations and not who is popular on twitter.
Starship and the booster already collectively carry 70 kiloton-tnt-equivalent masses of liquid methane and oxygen. As a weapon of mass destruction, it's hard to beat relativistic impact.
How do you calculate this? Starship has a propellant capacity of 1200 metric tons - 1.2 kilotons. Super heavy booster has 3400 tons, total of 4.6 kilotons, per wikipedia [1]. By weight, you need about a 4:1 ratio of O2:Methane for complete combustion (Starship is rumored to carry 22% methane). Which means you're getting about 0.92 kilotons of methane completely combusted. At 50-55MJ/kg, that gives you - roughly - 50 thousand gigajoules. A ton of TNT is 4.184 thousand gigajoules[2], which means that Starship+Super Heavy carries the energy-equivalent of about 12 kilotons of TNT [3][4].
[3] It can't explode all at once unless pre-mixed in perfect proportion, of course. What you'd really expect is an awfully big fireball + fire but not the same massive force all at once of a nuclear detonation.
[4] Or 50 terajoules (the ship) and .184 terajoules (TNT), which come out to the same thing, but I find gigajoules both more intuitive and more a more fun BTTF reference.
> As a weapon of mass destruction, it's hard to beat relativistic impact.
> relativistic impact
You... er, realise they're not actually starships, right? At the speeds they go at (or would go at if they could take off without exploding) there is no significant relativistic effect.
Surprisingly little, as the thing is mostly fuel — by the time it hits anything[0] it's almost empty and therefore very light.
It wouldn't even be like the effect of the planes on the WTC in 9/11, as planes use fuel continuously during flight, whereas spacecraft use almost all of it just to take off.
[0] which implicitly assumes the self-destruct still isn't working right
