TO WHAT GOAL?

Evening Post, Volume CXVIII, Issue 13, 16 July 1934, Page 10

TO WHAT GOAL?

FUTURE OF THE ROCKET

HARD WORK BY SERIOUS MEN

BUT NOT MOON FLIGHTS

A cabled message from Tukio anI nouncing the invention of a torpedo , rocked capable of traversing the strato- , sphere at 8000 kilometres per hour (5000 . miles per hour) once agaiu sots back , in the public mind the repute of rocket . transmission, particularly as the rocket ! torpedo story is improved by the assurance that this Japanese rocket is "im- ! mune from the American death ray,'' for [ the average man simply refuses to tako > rockets and rocket propulsion seriously. Probably, however, the average man is '_ wrong; at any rate, there are in soy- ; eral countries, including England, Ame- ; rica, Germany, Trance, and Japan, a ' good many thousand people, neither 1 cranks nor cranky, who tako rocket de--1 sign very seriously indeed. ! Fifty years ago there were people ' who took-.aviation seriously, though the average man looked upon the few who ' believed in human flight, other than ;by balloon, as undeniably mad. The ; Japanese story is not impossible, but it certainly loses authority by that reference to the "death ray" (which is ; not impossible either, of course). , What are the rocket believers and designers after? So much has been written of flights to the moon and to Majs that the serious side of tlftsir work has been lost an the atmosphere of polite ridicule. Flights to the moon are in the minds of the designers and those who provide funds for their costly experiments, but' only academically so: they are concerned with much more immediate problems, the first and most vital being how to design an efficient ' rocket for a flight of, say, 25 miles, not for 250,000 miles. AVhen the Wright, brothers, gave their whole time to the first practical aeroplane they did not talk of flying halfway round the earth: they wanted an aeroplane that would fly. The long-distance aeroplane has been developed since. So with serious ■rocket builders: they have great beliefs, but for the moment they are building in a small way to establish principles • from which, if the principles are sound, development will inevitably follow. THE MOON PLIGHT DREAM. Tjct us get the moon flight over and . done with' first* Mathematicians have calculated just what is the velocity necessary to defeat the gravitational pull of the earth—2s,ooo miles an hour, or C 664 miles a second—contending that if that velocity is reached by the consumption of tlio fuel the rocket will "coast" the rest of the way. Terrific fuel energy would be required to attain such a velocity, but it has been, suggested that it would be possiblo (some day) by means of a "step rocket." This would consist of a series of rockets, the smallest, at the nose, carrying tho passengers and a fraction.of tho fuel, the next carrying the first section and a large quantity of fuel, and the third, and largest, carrying a great deal of fuel and the other two as excess,-, or "pay load." The first rocket would complete the journey; the second and third would bo dropped ofi as their fuel was ex"haustcd. The figures have been worked out by an Austrian experimenter as follows:— FIRST STEP. fuel. Pay load. Structure. - Total. . Tons. : Tons. Tons. Tons. 60 10 10 80 SECOXD STEP. 480 80 80 040 THIRD STEP. 3840 640 640 5120 A fourth step would bring the total weight up to about that of a battleship, 40,000 tons. No, the rocket designer and experimenter is not concerned at present with flights to the nioon; he is convinced that there are uses for rockets much nearer home, uses which, as with the automobile and tlio aeroplane, may ; work a new and greater mechanical , revolutionyin the nex^ 30 or 50 years. HIGH VELOCITY ESSENTIAL. The best steam or internal combustion' engines have efficiencies (in return for fuel consumption) often below 25 per cent.; tho rocket, provided it went fast enough, would have an efficiency of almost 100 per cent.^ No wonder, then, that the rocket is seriously inquired into. Very high speed, however, is' essential to rocket efficiency, in the vicinity of a mile per second, or about double the velocity of a projectile as it leaves the muzzle of a modern field gun. The recognition of the necessity of such velocity has blasted the hopes of those early investigators who travelled a blind road believing that it led towards rocket automobiles or rocket-planes, but, as a writer in "Tho Scientific American" phrased it, there is no need to harness this Pegasus ton wheelbarrow. In tho lower portions of the earth's atmosphere such speeds would bo out of the. question, but tho density of the ' atmosphere falls ofCrapi'dly, and at.an altitude of ten miles there is only about 1 one4enth as much air as at sea-level. f Rockets could travel at their full speed in the stratosphere. A rocket might be shot from New "York to Paris in 50 minutes, or clean across the United States in about the same time. • But in fact, the fifty-minute flight ; across the Atlantio (let alone the con--1 trol of the rocket as it's destination is ' reached) is almost as far away in de- ■ velopment as tho flight through inter- : planetary spacer Present experiment i aims at the development o.f a . which will shoot straight up to a given altitude, carrying various recording in- . struments to gather data in the stratoi sphere, and returning gently to earth with their instruments. SEARCH FOR ROCKET FUELS. The first step is to find the right ; fuel. Gunpowder will definitely not do; ; for the purpose if. is ridiculously weak. 1 High explosives will not do; they are ; far too feeble.- Liquid oxygen and ' petrol get nearer tho requirement, for, correctly proportioned, this mixture 1 gives ten times tho power of T.N.T. * It is no stuff for amatours to play with, 1 and highly qualified investigators have 1 lost their lives in the work. Each country claims tho outstanding I ■ success, but America says that tho real I success to date was made when the ■ American Bocket Society shot a liquid fuel rocket near New York, demon- : strating tliat the liquid fuel system dei vised by them was a success. Actually the rocket burst at a height of about ; 300 feet because of excess pressure in ■ the oxygen tank. It is difficult for • a plain average i man, scornful over trips to the moon i by rocket,' to imagine that the members :of tho American Rocket Society whooped in. triumph when their rocket shot up 300 feet and burst, but that is - what they did do, for they knew that their idea= was sound and turned to again to build a better job.. : That burst rocket, 300 feet up, was 1 perhaps the first milestono on a new . road of rocket development, and no- : body can sec where that road leads to or will end.