This is great, I'm glad some people have continued doing work on NTR.<br /><br />I was doing some simple calcs with 130kN thrust and a guessed weight of a million kg. A one hour burn would add ~468m/s deltaV to such a craft... is this good enough? Is a million kg insane? I based it off the estimate of 685 metric tons referred to in the article, which sounded kinda ludicrous to me but thought it could be possible if you were bringing down vehicles and large, rigid-bodied habitats.<br /><br />Is the benefit really obvious with the hybrid nuclear-electrical system he was talking about? I mean, why not do an initial two hour burn instead of a one hour NTR burn followed by a sustained NEP propulsion? I love the idea of NEP in other situations but it seems like if you have an NTP system onboard then you should max it out. I'm guessing that 8, large, highpowered Ion-Propulsion drives would only impart about 50N of force on the craft. Is this ballpark right? <br /><br />^^ I'm talking about a Mars mission