A previous thread https://news.ycombinator.com/item?id=23132488 https://news.ycombinator.com/item?id=23132488 I still like to think if it existed it could be

A previous thread https://news.ycombinator.com/item?id=23132488 https://news.ycombinator.com/item?id=23132488 I still like to think if it existed it could be our ticket out of the solar system. (or a braking system for reentering if we ever made it that far)