A first spaceship S1 departs from earth and quickly accelerates to a velocity V = c/2. S1 travels the shortest path (dead heading) toward a distant planet Alpha so that it arrives in 20 years as measured by a clock on S1. One year after S1 is launched from earth as measured by a clock on the earth, a second spaceship S2 is launched along the same trajectory (we assume neither earth nor alpha have moved during this experiment). S2 quickly accelerates to a greater velocity than c/2 and at some point S2 overtakes S1. When S2 arrives at Alpha, the clock aboard S2 will read a lapse time of 10 years since it departed from earth. Both S1 and S2 move at uniform velocity, so each is a valid inertial system, but the proper clock rate of the S2 clock is 1/2 the proper clock rate of the S1 clock. Based upon the difference in proper rates - if observers on each spaceship take the measure of the other as S2 passes S1, will an observer in S1 arrive at the same conclusion about contraction and clock rate in the S2 frame as S1 determines about contraction and clock rate in the S2 frame?