>> sails, deploy Bussard ramjet, and then scoop interstellar
>> hydrogen.
>
>Use a ramjet and scoop interstellar hydrogen? It sounds
>interesting, basically because I can't visualize how it
>works...
It's been shown that in most of the galaxy, the density of interstellar hydrogen is too low to feed a Bussard Ramjet and make it work. At this point it's just an old, discredited sci-fi dream. Try "Tales of Known Space" by Larry Niven.
-PW