Hi, If I want my spacecraft to accelerate at a rate that produces 1 G for a set distance (half way to another solar system) then decelerate at the same rate for the second half of the trip, what formula would I use? I would like to calculate the peak speed of the ship and the time dialation experienced by the crew. My thoughts are to design the spacecraft so that the crew would experience Earth like 'gravity' while it accelerates, then at the half way point, the ship would flip 180 degrees so the crew would continue to experience the same 'gravity' while it slows for the second half of the trip. I also need to know how much time will pass for the crew. phyzguy gave me the formula for the time dilation but I don't know how to incorporate acceleration over time into it.