Suit, Will Travel Author Robert A. Heinlein's novel Have Space Suit—Will Travel (1958) drew both on these contemporary articles and on his experience designing pressure suits during World War II and featured a detailed description of a very realistic space suit with constant volume joints and fixed helmet and shoulder yoke, which was entered through a frontal gasketed zipper (similar to that in a drysuit). Front cover illustrations (one shown here, one linked to in its caption) for the novel obviously inspired by contemporary diving apparatus show its life-support backpack as a correctly drawn old-type open-circuit two-cylinder aqualung as used for scuba diving with manifold and large round regulator and A-clamp. The artist avoided the error found in most comic-strip drawings of old-type aqualungs, of drawing each breathing tube coming directly from a cylinder top and no regulator. But to make this type of aqualung (as shown here) work in space, its regulator's existing perforated "wet-side" cover would have to be replaced by a sealed cover with a spring-loaded exit valve to keep a breathable pressure on the "wet" side of the regulator diaphragm. And the whole breathing system would have to be checked for leaks which would be harmless in scuba diving but would blow in space vacuum. On the first image the breathing tubes run to a control panel on his chest, and the regulator can be seen. The image shows two spacesuits, whose helmets differ. One has a worklight on top; the other has two worklights, one on each side, and on top what is intended to represent a radio spike antenna and microwave horn antenna (two different antennas are also shown in a second book illustration, though the "microwave horn" antenna is incorrectly drawn attached by its wide end like an animal horn, instead of the correct musical-horn-like shape of a microwave horn antenna). On the second image the breathing tubes run to each side of the "chin" of his helmet, and the regulator is hidden behind his head. The spacesuits in these drawings differ much, but all depict the helmet base as being wide enough for the wearer to get it on over his head, showing that their artists had paid little attention to the writer's detailed descriptions. In a description of the spacesuit Heinlein appears to be confused about the various effects of oxygen toxicity and bends and nitrogen narcosis. Heinlein's description of pressure