NERVA was fine if you didn't start it up until you were in LEO and took care to avoid any trajectories that might involve Earth reentry. But even for manned fli

NERVA was fine if you didn't start it up until you were in LEO and took care to avoid any trajectories that might involve Earth reentry. But even for manned flight outside the atmosphere, shielding was an issue and servicing it was pretty much a suicide mission. Not insurmountable problems, but more than we needed for our modest goals at the time which didn't involve going beyond the Moon. http://www.wired.com/2012/09/nuclear-flight-system-definition-studies-1971/ http://www.wired.com/2012/09/nuclear-flight-system-definitio...