Voyages Interplanétaires et Energie Atomique.

An engineer’s technical assessment of whether atomic energy could power interplanetary travel, prefaced by physicist Maurice de Broglie. Richard-Foy works through the astronomical, dynamical, and thermodynamic constraints on a rocket voyage to Venus, Mars, or the Moon, then models an atomic-pile engine — a uranium fission reactor standing in for the combustion chamber, heating a working fluid that is ejected as reaction mass in place of a chemical propellant. He tabulates fuel consumption for different trajectories (as little as 4 kg of uranium per tonne of payload for a 50-hour lunar round trip, tens of kilograms per tonne for six-month Venus or Mars voyages) and works through problems of weight, atmospheric transit, and thermal protection.

His conclusion is notably cautious: interplanetary flight remained tied to conditions — new isothermal nozzles, heat-resistant materials, concentrated uranium-235 piles safe at high temperature — that seemed, in 1947, still very improbable; lunar flight, he judged, was comparatively nearer at hand.