A hard science fiction novel. Fifty men and women set out in the twenty-third century from Earth aboard an interstellar craft to travel to a planet thirty light-years away. But the ship's deceleration system is irreparably damaged when it hits a cloud of interstellar dust, and acceleration continues...

A hard science fiction novel. Fifty men and women set out in the twenty-third century from Earth aboard an interstellar craft to travel to a planet thirty light-years away. But the ship's deceleration system is irreparably damaged when it hits a cloud of interstellar dust, and acceleration continues toward light speed, tau zero.