From Insty, it turns out that NASA’s Orion is having a little problem with cost overruns. Who could have predicted that?
Of course the REAL problem with NASA’s Orion is that they stole the name from the real Orion, a nuclear spaceship design that could have given us the entire solar system decades ago if it weren’t for the nuclear test ban treaty.
A 1959 report by General Atomics explored the parameters of three different sizes of hypothetical Orion spacecraft:
Ship diameter 17–20 m 40 m 400 m Ship mass 300 t 1000–2000 t 8,000,000 t Number of bombs 540 1080 1080 Individual bomb mass 0.22 t 0.37–0.75 t 3.00 t
The biggest design above is the “super” Orion design; at 8 million tons, it could easily be a city. In interviews, the designers contemplated the large ship as a possible interstellar ark. This extreme design could be built with materials and techniques that could be obtained in 1958 or were anticipated to be available shortly after. The practical upper limit is likely to be higher with modern materials.
Most of the three tons of each of the “super” Orion’s propulsion units would be inert material such as polyethylene, or boron salts, used to transmit the force of the propulsion unit’s detonation to the Orion’s pusher plate, and absorb neutrons to minimize fallout. One design proposed by Freeman Dyson for the “Super Orion” called for the pusher plate to be composed primarily of uranium or a transuranic element so that upon reaching a nearby star system the plate could be converted to nuclear fuel.
The key is that this thing could have been operational with 1950’s tech. As far as I’m concerned, if Doctors Dyson and Pournelle said it was doable then it was. Nuclear power is still the only thing that’s going to allow us to get large amounts of mass into Earth orbit and beyond. Nothing else has enough specific impulse to do the job.
Update: Welcome Instapundit readers! Please don’t melt the servers. 🙂
Update: Welcome Transterrestrial Musings readers!
Update: More on scaling chemical rockets here.