File:Tsiolkovskiy rocket, Collected works, NASA TT F-237.en.png

We can read p. 86: "The liquefaction of hydrogen and oxygen involves no special difficulty."

We can read p. 86: "The liquefaction of hydrogen and oxygen involves no special difficulty. Hydrogen could be replaced by liquid or liquefied hydrocarbons, for example, by acetylene or oil. These liquids must be separated by a partition. Their temperature is very low; therefore it would be expedient to allow them to surronnd either jackets with circulating liquid metal or the tubes themselves."

We can read, p. 80 : "Lastly, rotation of the mouth of the tube might also serve as a means of keeping the projectile on course. The simplest means of steering the rocket would be dual control surfaces mounted externally, close to the mouth of the tube. As for preventing the rotation of the rocket about its longitudinal axis, this can be accomplished by rotating a plate located in the gas flow and aligned with the direction of this flow." [Editor's note: It is noteworthy that here Tsiolkovskiy anticipates the development of modern exhaust control vanes".]

In another text, "Jet Propulsion (Reaction motion)"^[1], dated 1932, we can read : "Two vertical rudders and two horizontal. These are rudders of direction and rudders of stability. The rudders function in the vacuum owing to the swiftly flying out products of combustion."

We can read, p. 78: "Visualize the following projectile: an elongated metal chamber (the shape of least resistance) equipped with electric light, oxygen, and means of absorbing carbon dioxide, odors, and other animal secretions; a chamber, in short, designed to protect not only various physical instruments but also a humanpilot (we shall consider the problem in its broadest terms ). The chamber is partly occupied by a large store of substances which, on being mixed, immediately form an explosive mass. This mixture, on exploding in a controlled and fairly uniform manner at a chosen point, flows in the form of hot gases through tubes with flared ends (Fig. 1), shaped like a cornucopia or a trumpet. These tubes are arranged lengthwise along the walls of the chamber. At the narrow end of the tube the explosives are mixed: this is where the dense, burning gases are obtained."