If a spaceship travels a distance of one light year as measured from earth in one year's time as measured from the spaceship what is the relative velocity for earth-ship. Also how far did the pilot travel according to the pilot and how long was the trip according to an earth-clock? I found the distance of a light year. I believe that i have to use gamma as a variable to find u but i am stuck as i don't know how to get at finding the velocity for the spaceship in order to use the time dilation and length contraction formulas. any help would be greatly appreciated.