THE ORION PROJECT, with which I was involved about 10 years ago, aimed to build space ships powered by nuclear explosions. We began work on Orion after the Russian Sputnik went up and before the US was committed to a big space program with chemical propulsion. We felt then that there was a reasonable chance that the US could jump directly into nuclear propulsion and avoid building enormous chemical rockets like Saturn V. Our plan was to send ships to Mars and Venus by 1968, at a cost that would have been only a fraction of what is now spent on the Apollo program. We never got the green light; so nobody can be sure if our schemes were sound. I am not against the Apollo program; I much prefer it to no program at all. Still, I believe that fundamentally a Saturn V bears the same relation to an Orion ship as the majestic airships of the 1930's bore to the Boeing 707. The airships were huge, flimsy, with a payload absurdly small in comparison to their size, just like the Apollo ships.
Two space‐ship designs show that nuclear‐bomb detonations could take over from chemical propulsion as an energy source for long‐range space travel. If our economic growth continues at its present rate, interstellar voyages with ships like these could begin in about 200 years' time.