Another thing that help you get further once the rad is pinged is to shut down the engine before it seizes up on you. If you shut it down and glide for awhile the temps start dropping. Once they get pretty low you can fire it up and climb like heck, it gets into the red shut it down and glide again. I've gone 1 sector using this method and starting at 7k. I also usually use the engine to help me land and just let it seize up during touchdown.