The nuclear-electric drive is dead

Robert Zubrin's 2008 How To Live On Mars in its first chapter offers three means of interplanetary transport. First, cyclers; third, riding the freight. In between the chapter mentions the nukey ride to glory. The first and last, are clear: you use quick-thrust low-impulse, like ol' Boom Boom or a tether, twice: to lock into a Hohmann or cycler (or, for faraway journeys, bi-elliptic), and then to unlock you out again. I am here looking at the second option, pp. 5-7, with continuous propulsion. That is the one Zubrin didn't like. (Well okay, he doesn't like the cyclers either; and honestly neither will anyone on Earth.)

This second option is the nuclear-electric ion-drive, which Zubrin here called out as a NASA boondoggle. It's been rattling around awhile. Zubrin calculates, or maybe remembers, that it takes a year to get to a respectable speed, and maybe another year to get back down again. By inner-planet timescales you may as well use "the" cycler - implicitly Aldrin's 146-day one.

Whilst I'm sharing, Nuclear-Electric hasn't been on my "radar" this past year. (As NASA themselves would put it.) I just don't think it can scale; unless you are lugging a massive reactor behind you, and not a very, [sunglasses] e-fission-t, reactor. For that whole genre NASA it/themself last year were looking more to solar-assisted electric. Like I was. And I want that one for inner-system station-keeping only.

NASA seem to be backing off nuclear-assisted electric. On 12 February they were talking up thermal. Ay-hup, that's our NERVA! - another concept that's been knocking around NASA awhile...

Back in September 2019, the ToughSF site considered a slew of NERVA and hybrid-NERVA. We could further consider fusion or even Zubrin's own saltwater reactor.

Back to NASA's NED: file that away with Alex Cheung's ¹¹boron/hydrogen fusion reaction which also hasn't gone anywhere since conception, the early 2000s here UPDATE 4/18/23: we might be doing better!. Each seemed like a good idea at the time. Maybe 'twas even Zubrin's book helped convince NASA (belatedly) that their ion drive was for the birds. If so, I thank him.

If we do get NERVA to Mars this does, however, cost Zoob's readers some immersion into his argument. Also, I'd not advise riding the freight like a hobo if the freight isn't lined with water-ice and/or lithium hydrates. Bremsstrahlung, mein Kapitan.