published in Moscow. biti Thi ty | | BEGINNING A=NEW SERIAL os is the first of a series of extracts, appearing exclusively in the Pacific Tribune, from a remarkable new Soviet book, Interp lanetary Travel, by A. Sternfeld, recently An English edition of the book’is to be published in, Britain soon. This first extract deals with the problems of overcoming the earth’s gravity, already suc- cessfully solved by Soviet scientists. HE EARTH, one of the nine large planets of the solar System, travels at a great speed in airless space along an. al- Most circular orbit around the Sun, at a distance of over 90 Million miles from it. This dis- tance is taken a sone astronmi- Cal unit. TThe other eight large plan- ets — asteroids — travel ap- Provixately in the plane of the Same orbit. Interplanetary space is limit- €d by the orbit of Pluto, the Outermost planet of the solar System, which is separated from the sun by a distance of Nearly 3,750 million miles. It is this bounndless. ex- Panse that space ships will Cross, making use of the sun’s attraction, or struggling against it and evading collision With’ wandering meteors and Swarms of asteroids. What prevents us from lauching a rocket into space? The major obstacle is the force of gravity. All things around us pull at ach other, but we do not feel It because their power of at- traction is too weak. On the ther hand we always feel ter- Testrial gravity. Ts it possible for a rocket to leave the earth and never to Teturn? _per second the Yes, it is. Let us imagine that a horizontal launching site has been constructed on a high mountain, where air is no longer an obstacle to the roc- ket’s flight. : A rocket launched from such a site at a certain speed would follow a steep trajectory and fall at a certain distance from the mountain. The speed of the rocket can be increased to a point where the curve of the rocket’s tra- jectory is the same as that of the earth’s surface. As soon as this point is reached the rocket can fly around the earth and circle it again and again. Why does a body not fall to earth at this speed? When an aircraft flies around the earth, along the equator or a meridian, it is affected by a centrifugal force which in- creases in proportion to its speed. This force is in opposition to the pull of gravity and strives to lift. the aircraft away from the earth. At low speeds it is almost unnoticeable, but when the speed reaches almost five miles centrifugal force equals the force of gravity and neutralizes it. This a from the Like Smoked Salmon? Here's a Bargain to You (No Middleman) Fisherman FROM OPERATION ‘STRIKE RELIEF’ ORDER NOW TAtlow 3254 UNITED FISHERMEN and ALLIED WORKERS UNION - ~ is what we call the first astro- nautical speed. And at what speed must a body travel if dt is to over- come the earth’s gravify and fly off into space? The earth’s gravitational pull, like that of the other celestial bodies, decreases as one moves away from its centre. In order to free a body from a planet’s gravitational field, the same amount of work has to be performed as for lifting it to a height equal to the planet’s radius, assuming that the gravitational force does not change as the body recedes from the planet’s centre. We can accomplish that by giving the body a certain speed near the surface of the earth. A body going at that speed would travel along a parabola, and this is the origin -of the term parabolic speed, which is also known as the second astro- nautical speed or “the speed of escape.” At the earth’s surface it is seven miles per second. To facilitate calculation I have assumed that the body is attracted only by the earth. Actually, however, it is also affected by the sun’s gravita- tional field. Calculations show that a speed of not less than ten miles per second is required to set a body free from the gravi- tational fields of the earth and the sun. ‘ This is called the third astro- nautical speed. Bx It is generally accepted that any future space ship will be rocket driven. Travelling by rocket is quite safe because the rocket, as dis- tinct from an artillery shell, gains momentum gradually. Since the speed of a rocket- propelled spaceship through the atmosphere will be rela- tively low, the ship will not with much air resistance, and heat due ta friction will be in- significant. What is the principle of the rocket’s motion? The type of rocket with a gunpowder charge that is launched at a carnival cannot be used as a motor for the spaceship, because of the very high pressure set up by the combustion of gases, The liquid-fuel rockets ex- tensively used nowadays are superior to gunpowder rockets in this respect. Both gunpowder rockets and liquid-fuel rockets depend for the steadiness of their flight on air fins and rudders. But these are of no use once the rocket has left the earth’s atmosphere and emerged into space. What are the astronauts to do if the rocket is deflected from its route? This problem was solved by K. E. Tsiolkovsky, who sug- gested that rudders be placed in the stream of gas emitted from the nozzle in order to change the direction of the rockets flight in empty space. w On what factors does the rocket’s speed of travel de- pend? In empty space, beyond the reach of gravitational fields, the velocity that can be at- tained by a rocket depends on the speed with which the gases leave. the nozzle and the amount consumed. In view of this, use will be made of those fuels which pro- duce the greatest possible ex- haust velocity, for example oxygen and hydrogen. Nitric acid and hydrazine (a chemical combination of nitro- gen) are more economical, in- asmuch as these liquids are easy to handle and can be con- tained in small tanks. Other liquid-fuel rocket pro- pellents are benzine, turpen- tine, paraffin, etc., with hydro- chloric acid, hydrogen per- oxide, etc., serving as oxi- dizers. Thermo - chemical (conven- tional) propellents produce ex- haust velocities of about one and one half mile sper second, but there are good reasons for believing that a speed of two and one half miles per second can be reached, which would simplify the problem of con- structing a spaceship. Another method of increas- ing the rocket’s speed and range is to launch it with an auxiliary rocket. When ‘the latter uses up all its fuel it is automatically jettisoned, the touch-down being by para- chute. The main rocket is fired only when the auxiliary has done its job — that is when it has reached a certain height and speed, and it can ‘therefore climb higher than an ordinary rocket. To increase exhaust velocity, conventional propellents should be replaced by nuclear propellents. Modern physics has succeed- ed in converting a number of chemical elements into other elements. In certain cases the process is accompanied by a release of atomic energy. October 25, 1957 — The conquest of space A material that produces such energy is known as a nuclear propellent, a small quantity of which contains to convert certain liquids (for example, liquid hydrogen or helium) into gas and then to expell it from the rocket. Atomic energy can be used enormous energy. Nuclear propellent with a liquid or gas is called “atomic fuel.” One must bear in mind that the terms “nuclear fuel’ ’are used here only conventionally, since the release of atomic energy and its transfer to an inert body bear no resembl- ance to the process of burning as we know it. In an atomic rocket the gases will leave the nozzle at a speed of several dozen miles per sec- ond, and the greater the ex- haust velocity the less fuel is required for interplanetary travel. This is a big advantage ‘of the atomic rocket. Although the atomic rocket does not differ in principle from the ordinary types of rockets, fhere are a number of technical difficulties pre- venting its construction. In the first place the extra- ordinary high temperatures and pressures arising in the atomic rocket must be reduced because no metal can with- stand them. Secondly, measures must be taken to protect the astronauts from the radioactive radiations which are released at the same time as atomic energy. To tackle the problem sec- cessfully a material must be devised that would absorb such _ radiations and would, at the same time, be light, be- cause excessive weight would considerably reduce the rocket’s range. ® A second extract on space- ship desgn will appear next week. Gcs Installations FURNACES — STOVES WATER HEATERS Harry C. Weinstein GAS CONTRACTOR 692 East Hastings MUtual 3-5044 Res.: AL. 2991-L FREE ESTIMATES PACIFIC TRIBUNE—PAGE 9