1. The problem statement, all variables and given/known data The distance from Planet X to a nearby star is 12 Light-Years (a light year is the distance light travels in 1 year as measured in the rest frame of Planet X). (A) How fast must a spaceship travel from Planet X to the star in order to reach the star in 7 years according to a clock fixed on the spaceship? (B) How long would the trip take according to a clock fixed on Planet X? (C) What is the distance from Planet X to the nearby star, according to an astronaut on the spaceship? 2. Relevant equations Time-dilation and length-contraction equations. 3. The attempt at a solution (A) Using the only numbers the problem statement provides so far, I have a distance, and a change in time. Using the distance between planet x and the star (12 light years) and the time interval (7 years), obviously I end up with a number that is greater than the speed of light. v = (distance)/(time) = 1.713 C This is my speed bump. I don't believe I can approach the rest of the problem using this as my spaceship's velocity, seeing as all relevant equations become imaginary. I must be missing a key point as far as reference frames go and in getting the appropriate velocity of the spaceship, so what am I doing wrong from get go?