On the other hand, there is always the far end of the Orion research: the super-Orion propelled by hydrogen fusion bombs instead of small fission ones. [Freeman] Dyson wrote,
"... A ship with a million-ton payload could escape from the Earth with the expenditure of about a thousand H-bombs with yields of a few megatons. The fuel cost of such a mission would be about 5 cents per pound of payload at present prices. Each bomb would be surrounded by a thousand tons of inert propellant material, and it would be easy to load this material with boron to such an extent that practically no neutrons escape to the atmosphere. The atmospheric contamination would only arise from tritium and from fission products. Preliminary studies indicate that the tritium contamination from such a series of high-yield explosions would not approach biologically significant levels."
They estimated that the biggest ship they could get off the ground would be about 8 million tons. For comparison, a modern high-end cruise ship grosses 126,000 tons and carries 3000 people. [236] An 8 million ton ship could carry something like 200,000 people, in similar luxury.
One key fact about the Orion technology was that the total atmospheric contamination for a launch was roughly the same no matter what size the ship; so that there would be an impetus toward larger ones.
