This is not just a curiosity though. Nuclear pulse propulsion like Orion is actually the most advanced form of space propulsion that is within technical reach and doesn't use science fiction ingredients like large amounts of antimatter. When you read the article, you see that Orion was considered quite doable even decades ago. There actually is one system that would be even more efficient than Orion, the Medusa:
https://en.wikipedia.org/wiki/Nuclear_pulse_propulsion#Medus...
Though the Medusa design is less fleshed out than Orion.