Current regulations bar NASA from building or researching fueled nuclear devices I'm not sure what the author means here, but the Mars Curiosity Rover (on its

Current regulations bar NASA from building or researching fueled nuclear devices I'm not sure what the author means here, but the Mars Curiosity Rover (on its way to Mars right now) is powered by a nuclear device (an RTG). Maybe NASA just isn't allowed to pursue the (real) project Orion-type spacecraft anymore?