Authored in 1958, a year after the Russians launched Sputnik into orbit, TOM SWIFT IN THE RACE TO THE MOON, proved prophetic. Additionally, Tom named the craft CHALLENGER. The space race opponent who contested Tom in the contest to reach the Moon first was a people called the "Brungarians." Though no nation called Brungary existed in 1958, the name sounded very much like a communist nation of the cold war era.
Extremely intriguing is Tom Swift's space ship and its propulsion system described on page two: The cover art depicts the craft which looks like a gyroscope. A core box-type cabin hung suspended amidst a spherical framework of track-rails. The miraculous vehicle could go "anywhere in the solar system with no stops for refueling." Unlike traditional rockets, it burned no fuel. Its energy source was solar radiation. In Tom's words, "My craft's power units will change this (solar) energy into electric current for running a super-repelatron." Readers wondering what in the universe is a "super-repelatron" are told by the author, "Tom's basic reasearch had led him to the discovery of a previously unknown electromagnetic radiation given off by each element and its isotopes. As a result of this discovery, Tom had invented the Swift spectroscope... Tom had found that by having this radiation out of phase with the natural radiation of the atom, a repelling force was set up. This force, when used to hold off sea water, had made it possible to tap helium-gas wells on the ocean bottom..."
The author has given Tom Swift a propulsion system whose characteristics can wonderfully be adapted to countless vehicles, inventions, and exciting wonders. It, as a science fiction entity, gives the story's hero wide latitude in the scope of his undertakings. It is equivalent to H.G. Wells's invention "Cavorite." Wells's antigravity shield propelled his craft to the Moon just as Tom Swift reached the Earth's satellite with a super-repelatron propulsion system.
Since the repelatron effect is based on solar radiation, a launch would probably only succeed in daylight. Additionally, performance would be severely restricted on cloudy days. Since the strength of the Sun's radiation falls off considerably with distance from the solar star, the repelatron engine's performance in deep space (beyond Mar's orbit) likely would ebb. Of course, none of these considerations are mentioned in the story.