I have been reading a bit lately about project orion and the NERVA project. Project orion seems like such a crazy project that you cant help to love it Im not suprised it got shut down however. But is there any research going on anymore in the states or any other country that is similar to NERVA? As I understand it NASA's recent Prometheus project was oriented towards using reactors for electricity production to power equipment and ion engines. But no nuclear thermal propulsion? Is nuclear thermal propulsion research more or less dead all over the world right now?