[natcombs]

Using nuclear bombs for propulsion was estimated to make it to Mars and back in 4 weeks. First time I heard of this, I thought it was a joke.

https://en.wikipedia.org/wiki/Nuclear_pulse_propulsion

The project Orion study anticipated a one-way trip could reach Alpha Centauri in as short as 133 years

[jandrese]

I would take the figures from Project Orion with a grain of salt. It was very much a cocktail napkin exercise.