I see that Brian Wang is continuing to post on the potential benefits of nuclear-explosion propulsion, here and here (where he takes on Charlie Stross), and here, where he talks about it in the context of unmanned Mars missions and a high-speed asteroid interceptor.
I do think that there’s potential for this vehicle off planet, but I remain highly skeptical that it will ever launch payloads from earth, regardless of how theoretically cheap it might be. Particularly in the Age of Obama.
And frankly, when I read things like:
Nuclear Orion can achieve launch costs of less than $1/kg and perhaps a tiny fraction of that.
…it reminds me of the old claims from the early days of nuclear power that it would be “too cheap to meter.”
Actually, he understates Shuttle costs as being “$5000 to $6000 per pound,” even if it is an “accepted figure.” At current flight rates, I would guess that (at least to ISS), the current costs are about a billion per flight for about 40,000 (or less) lbs, or more like $25,000/lb (or more, depending on the payload). Which makes Orion look even better, of course. But it also displays my long-standing claim that the single most sensitive variable with regard to launch costs is flight rate, and any vehicle design consideration is a secondary matter.
Small and Expensive Versus Big and Possibly Infrequent Space Launch
The implication is that small is intrinsically expensive. But it’s not.
Small is only expensive when a) you throw the vehicle away and b) you don’t fly it very much. I would suggest that Brian read this piece on the subject of the reasons for high launch costs, which I wrote over four years ago to allay exactly this kind of misunderstanding, and (if he can afford the time and money — it’s really a bargain at the cost if one can get to Phoenix) attend the Space Access conference a month from now, where he can get up to speed on the current state of chemical-rocket launch technology (and its economics and business prospects).