Another is not to fight it, and let them go. The closest thing to a torch drive possible with modern day engineering after the NSWR is the open cycle gas core rocket.
Thrust in meganewtons, and 1000+ ISP
I’m thinking of something like an interstellar flyby probe for the Centauri system. It wouldn’t be able to stop or do much course correction but you could send basically an autonomous space telescope that transmitted back observations. It would be able to see planets in the system much better than we can from here.
Do you realize how big space is?
Do you understand how much radiation it is in space? All human nuclear experiments in 20th century together wouldn't be even a rounding error there.
> They were ultimately able to recover twelve large pieces of the satellite, ten of which were radioactive.[1] These pieces displayed radioactivity of up to 1.1 sieverts per hour, yet they only comprised an estimated 1% of the fuel. One fragment had a radiation level of 500 R/h, which "is sufficient to kill a person ... remaining in contact with the piece for a few hours."
A more pragmatic argument is that, after the fission of literal tonnes of plutonium in the atmosphere in the previous century, the small risk of losing a few kg more here or there pales in comparison. Even all those RORSATs barely register in comparison to that.