The cover of the July 1947 AMAZING STORIES issue depicts a scene from the lead "amazing story" title HIDDEN CITY. On page 23 of the tale of a trip to the Moon, the author describes the lunar rocket FRONTIER: "To those who possesed an artistic rather than a technical sense, the FRONTIER would have seemed a curiously ungainly craft. It completely lacked the cigar-shaped symmetry which one more or less unconsciously expected of a vessel built to navidate the void between worlds. From a slim, pointed bow widened to a broad, flaring stern, a design which gave the ship a disproportionate, rear-heavy appearance...To a rocket engineer, however, the FRONTIER would have seemed a marvel of compactness, utility, and strength. That clumsy-looking stern would have been seen at once as the only means of locating the huge jet tubes with a minimum of space and a maximum of mechanical efficiency. And when the difficulties of taking off and landing in a gravitational pull were considered, certain other advantages of its design became apparent: in taking off, it would have a high angle of trajectory which would conserve fuel; in landing - accomplished stern foremost - it would have greater stability, reducing the danger of its losing balance and crashing when settling down on its jets...
The FRONTIER's flaring stern was channeled to form four great thick vanes or fins. Seen from the rear, these made a cruciform outline, with a large exhaust tube in the center and four smaller ones at the tip of each arm. The smaller tubes slanted outward, so that their jet streams would emerge at an angle relative to the stream from the central tube, thus making it possible while in flight to steer the ship in any desired direction... The FRONTIER was approximately sixty feet long. Less than a third of this was passenger space; the rest was almost completely taken up by fuel tanks and propulsion engines. The hull was of a smoothy-welded, highly-polished beryllo-steel alloy, tough enough to deflect small, low velocity meteorites, though all knew it would be no proof against large ones traveling at high speed. Only an impossible thick hull would resist penetration by the latter...Thick, blunt wings projected from the vessel's sides, near the bow. These were telescoped at present, but could be extended for use in the atmosphere. Amidship, at the top, was a transparent quartzite pilot shell. Quartzite was the latest product of scientific ingeniuity; enormoulsly strong, it at once permitted clear visibility and acted as a shield against both harmful space radiations and the burning ultra-violet rays of the sun."
Design of the spacesuits in HIDDEN CITY is intriguing. "They donned more appropriate clothing, and over this pulled specially-built, one-piece suits, heavy but flexible, made of strong, pastic-coated fabric. Airtight, electrically-warmed, and with an independent oxygen supply in tanks fastened to the shoulders, the garments were intended as protection against loss of air, heat, and pressure, as might happen if the ship were struck by meteorites. There were helmets to accompany the suits, which, however, Dall and Grontenac did not put on at once."
Next, the author described the crew station of the FRONTIER: "Then, making their farewells among the staff, they entered the ship. Dall sealed the entrance hatch, and followed Frontenac up to the control room. They strapped themselves into their huge, thickly rubber-padded spring-cushioned seats, then waited tensely for the signal which would indicate that the field had...cleared."
Struck by two meteoroids, FRONTIER's oxygen tanks are damaged. Only enough oxygen remains to reach the Moon. There is no hope of a return to Earth. The two astronauts orbit behind the Moon. They observe the side never seen before. AMAZING! They find a "hidden city" resides there. Their salvation!