[api]

Use it for the later stages in a many stage interstellar rocket. First stages are chemical, then NERVA style contained nuclear rockets, then open cycle nuclear when you are already well past solar system escape velocity.

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.