This may be old territory, but I am relatively (no pun intended) new to this stuff, so I apologize if I'm bringing up things that maybe I should have learned already or found among older posts. I have a little thought experiment that I would like your opinions on. Let's suppose we have a square platform in space and two rockets on either side of it--to visualize, one is pointing "up" and the other is pointing "down." The two rockets launch and head in 180-degree opposite directions, each accelerating to just over 1/2 the speed of light. Can one rocket send a transmission that the other is capable of receiving, or will the each rocket exceed the light cone of the other? If they can each receive signals from the other, how can the signal traverse the distance without exceeding the speed of light? If they can't receive signals from each other, has one traveled faster than the speed of light when using the other rocket's cockpit as the inertial frame of reference?