Nuclear power generator uses radioactive particle emission to stimulate fluorescent material which then lights up photoelectric cell. It's called PIDEC: http://www.physorg.com/news158848950.html http://nextbigfuture.com/2009/04/direct-conversion-of-nuclear-power-to.html They're claiming upto 40% conversion efficiency, which is pretty good. They're also saying it could make for a much more compact and portable nuclear powerplant. I'm wondering if that could make it suitable for spacecraft. For instance, it could be used to power an ion-engine, or a VASIMR type of rocket. This could make SSTO practical. At the least, it should be suitable for powering space probes (eg. rovers) Can anyone comment on the feasibility of this design?