NASA again looking at Nuclear Rockets
The Nerva that we all love (and the Nuclear Lightbulb from Porkjet's old mod Atomic Age) are both based on real research done in the late 50's, 60's and 70's. The goal was to replace the Saturn 1b upper stage. It was tabled both because of the change in direction of NASA, overall public fear of nuclear energy and international treaties regarding nuclear energy in space.
Well, they are looking at it again. See the following, this is a current article:
https://www.nasa.gov/centers/mar
Hey look almost all the work already done for me.
Without having an enormous rocket, there is a practical limit to how much dV something with an ISP of 325 can get you. Unfortunately, as pointed out, NTRs are considerably heavier than their chemical counterparts. In fact, they pretty much always will be because there is a limit to how small they can be made. So even if TWR had no bearing on the decision to use one, the smallest an NTR can be made and still function is 1770 kg per the study
