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Aviation History
1957
1957 - 1571.PDF
FLIGHT, 25 October 1957 659 THE ASTRONAUTICAL CONGRESS Satellites a Topical Subject at I.A.F. Barcelona Meeting By KENNETH W. GATLAND* HIGHLIGHTING this year's Congress of the InternationalAstronautical Federation, held in Barcelona, was the excit-ing news of the Russian satellite, though it was not a littlefrustrating to be rushing off to Spain on the morning of Saturday, October 5, just as the first details were coming through. Communications with the outside world from Barcelona arenot good at the best of times, and with the lines jammed by correspondents reporting the Congress little could be done butawait the arrival of the previous day's English newspapers, or attempt to fathom the headlines of the Spanish Press. This dearthof information at so dramatic a moment in history resulted in a number of lighthearted rumours—one that against the rising floodof scientific acclaim for the Soviet achievement, mutterings of "utter bilge" were still to be heard emanating from the ancienttowers of the Royal Observatory; and another that the Americans had shot down the Russian satellite, using their balloon-launchedrocket, Far-Side. Among the 300 participants at this year's proceedings were anumber of well-known personalities in the scientific world, includ- ing Prof. Theodore von Karman, Prof. S. F. Singer, of MOUSEsatellite fame, Prof. L. I. Sedov of the U.S.S.R. Academy of Sciences, Major David Simons, the U.S. high-altitude balloonist,Mr. A. V. Cleaver of Rolls-Royce rocket-engine department, Dr. L. R. Shepherd of A.E.R.E. Harwell, and Mr. Andrew G. Haley,the authority on international law, who succeeds Dr. Shepherd as I.A.F. president. Of great significance in view of the growing pace of astronauticaldevelopment was the decision to implement a proposal of the I.A.F. International Affairs Committee to consider the legal aspectsof space-flight. It was becoming imperative to establish the boun- daries of air-law and space-law, said the chairman, Mr. Haley, anda working committee, comprising the best available legal and scientific minds, should be set up to draft recommendations forsubmission to the Secretary-General of the United Nations. It might comprise seven distinguished persons, four lawyers and threephysicists, and it was proposed that Prof. John Cobb Cooper, of the Institute of Aeronautical Law, should be invited to act aschairman. Prof. Sedov was asked to suggest the names of two Soviet representatives, others to be drawn from Western Europe,the United States and South America. The proposal was accepted unanimously, and before the Congress ended Mr. Haley was ableto report that Prof. Cobb Cooper had consented to be chairman. Over 40 papers were presented at the various technical sessions,approximately one quarter of them dealing with some aspect of artificial satellites and thus having highly topical interest. Onesuch contribution, by H. H. Koelle of Redstone Arsenal (the ex-Peenemiinde group under Dr. Werner von Braun) dealt withthe OptimizationojOrbital Payloads and included some discussion on the possible nature of the Russian satellite launching vehicle.It would be logical, said Mr. Koelle, to assume that the Russians were using the powerful 264,0001b-thrust booster of their inter-mediate ballistic missile as the basic booster of their three-stage orbital carrier and the improved 77,0001b-thrust V-2 missile as thesecond stage. (The development of this combination goes back as far as 1948.) Such an approach, he suggested, was very attractivebecause it had the advantage of using proven hardware with established reliability. The job remaining to be done was todevelop a third stage and to mate it properly with the other two, possibly using the improved Wasserfall engine of about 20,000 lbthrust. In view of the greater design latitude, all control would be incorporated in the third stage (instead of in the second stage,as in the much smaller American Vanguard rocket), which would thus have a better chance of placing the satellite in a satisfactoryorbit. Disadvantages of this solution, he said, were three different propellant combinations for the missile and a total structuralfactor (ratio of dry weight to launching weight) which was not representative of the present state of the art. Nevertheless, thisthree-stage configuration would offer up to ten times the payload capacity of the first American orbital vehicle. With the first artificial satellite already in orbit, it was naturalthat interest should centre on the Congress papers concerning the tracking of satellites. In a paper by Dr. F. L. Whipple and J. A.Hyrek of the Smithsonian Astrophysical Observatory, details were given of the visual search and acquisition programme, Moon-watch, and the high-precision photographic tracking programme. Moonwatch consists of volunteer groups, each with twelve ormore non-professional observers equipped with small telescopes. These telescopes, of 50 mm aperture and 12 deg field, will covera large arc of the meridian at twilight periods during the early stages of satellite launchings and during the very last stages when the satellites finally burn out in the lower atmosphere. Nearly100 Moonwatch teams are now active in the United States and another 50 elsewhere, in places as far apart as Germany, Spainand South America. Observers are required to note the time of passage of the satellite to the nearest second of time and its positionto within a degree and transmit this information by telephone to the computation centre located at Cambridge, Massachusetts,where, on the basis of several reports, the satellite's position can be worked out by triangulation. The photographic programme, operated by professionalastronomers, centres on the use of the Baker-Nunn cameras, developed from the famous Schmidt meteor camera. Twelvephotographic stations are being established, two in the United States and one each in Hawaii, Japan, India, Iran, Spain, theNetherlands Antilles, Peru, Argentine, South Africa and Australia. A similar report, concerning visual observations of earthsatellites in the U.S.S.R., was given in faultless English by attrac- tive Mrs. A. G. Masevich of the Soviet Academy of Sciences. Likethe instrument recommended for the American Moonwatch programme, the Russian observing telescope has a 50 mm aper-ture, with a field of vision of nearly 11 deg. There are at present 67 visual-observation stations at various places in the U.S.S.R.where suitable weather is probable. Later, on behalf of the Soviet Academy, Mrs. Masevich pre-sented the Spanish Astronautical Society (hosts at this year's Congress) with a beautifully finished example of the Russianinstrument. A few days afterwards, at the concluding dinner, Mrs. Masevich—by now firmly established as the darling of theCongress—was presented by Prof, von Karman with a close- fitting claret-red hat, styled as a "satellite" with decorative antenna.Reliable estimates of the time for which close-orbit satellites will remain circling the Earth are difficult to obtain, because upperair conditions are still only vaguely known. This problem was considered in a paper by three Soviet scientists, D. E. Okhot-simsky, T. M. Eneiev and G. P. Taratynova, who have reduced it to a series of integral curves. The chart and tables thus obtainedmake it possible to determine rapidly the time of stay by multiply- ing the result taken from the table of the chart by some numberwhich is a simple function of the basic satellite parameters. Inte- gration of the equations was made on the fast computer of theU.S.S.R. Academy of Sciences. A third Russian paper, by five authors, dealt with artificialsatellites for the study of cosmic radiation. Details were given of recording apparatus used in these experiments, which has beendeveloped by the Academy of Sciences and Moscow University to yield information on variations of the primary cosmic-rayintensity and in particular on the low-energy particle flux. The future development of artificial satellites as relay stationsfor radio and television was considered by R. P. Haviland, of the missiles and ordnance systems department, General Electric Co.,in his paper The Communication Satellite. The use of the satel- lite vehicle as a base for communication purposes above theatmosphere was originally proposed by A. C. Clarke of the B.I.S. in 1945, and in this paper Haviland examines the proposal in somedetail in order to arrive at the optimum conditions for the design and operation of such services. What makes the technique soattractive is, of course, the height of operation—equivalent to a radio station having an impossibly high antenna mast. Thisextends the line-of-sight coverage, and makes the use of very high radio frequencies for long-range communication entirely feasible. The more sophisticated satellites needed to perform these andother functions will require some form of attitude control (e.g., for uniform alignment of radio arrays, TV cameras, telescopes,etc.); and in a mathematical paper, R. E. Roberson (autonetics division, North American Aviation) considered the choice of thereference axis and the means of applying control torques necessary to impart sufficient angular acceleration to keep the satellitealigned with the chosen datum. One of the most promising tech- niques is the use of power-driven flywheels, which provide aninertial reaction torque when accelerated relative to the satellite's frame; the small electric motors required for this purpose mightdraw their power from solar batteries (which convert sunlight directly into electricity), thereby rendering the system virtuallyself-supporting. Selenoid Satellites was the subject chosen by W. B. Klempererand E. T. Benedikt (missiles engineering department, Douglas * Mr. Gotland, who is vice-chairman of the British InterplanetarySociety, was British delegate to the Congress. He is the author of the "Flight" book "Development of the Guided Missile."
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