Black Hole Starship(en.wikipedia.org)
en.wikipedia.org
Black Hole Starship
http://en.wikipedia.org/wiki/Black_hole_starship
2 comments
Probably the most "likely" of all the "fraction of lightspeed" (30-50%) starships.
I seem to remember a black hole powered starship being mentioned in a 1978 book edited by Jerry Pournelle called "Black Holes and Other Marvels"