ventional receiver and a separate oscillator for the frequency of 40 Mc±2 Kc. such as the KK-6 quartz calibrator. In this case the receiver oscillator is switched off and tape recorder is made to record beats formed by the received signal and the calibration frequencies (R. 13).

For this purpose, the terminal marked "coupling" of the calibrator is weakly coupled with the antenna input of the receiver. This method eliminates frequency shifts of the heterodyne oscillator, since the beats are the result of two stabilized frequencies. Both frequencies must be within the frequency band of tuned receiver. Assuming that the exact frequency of the transmitter is 40.022 Mc., the 32d harmonic of the KK-6 calibrator (40,000 Mc.) will be nearest to the signal. The amplitude of this harmonic at the calibrator output is very low, but it will be amplified along with the signal to a level which renders detected beats strong enough for tape recording (R. 13).

Before observation begins the receiver is tuned to 40.000 Mc. with the quartz calibrator. The tape recorder should be turned on as soon as signals from the satellite become audible. Time marks must be recorded on the tape along with signals in order to determine the time of passage. It is possible that special time signals will be broadcast for the purpose. If not, it is necessary at the end or recording to dictate into the recorder the exact time in hours, minutes, and seconds. The clock, of course, must be checked by time signals. The preferred frequency for determining the time of passage by the Doppler effect is 40 Mc. On this frequency the effect is much more pronounced than on the 20 Mc. frequency (R. 13).

The purpose of ionospheric observations is to determine the strength of receiving signals. Measurements are made at the output of the receiver by means of the IV-4 output meter or by a VTVM such as a TT-1, VKS-7, and others. The 20 Mc. signal should be used for this since it is more sensitive to ionospheric phenomena. However, by recording the output readings of both receivers simultaneously, it is possible to obtain information about the ionosphere. The information can be recorded on a single tape. In playback the output of the receiver is connected to an oscillograph. The amplitude of each signal can be measured directly on the screen. The high-frequency signals should not fall into the rolloff section of the frequency curve of the receiver. Shifts in the relation of the short wave signal to that of the ultra-short wave, reflect a change in conditions of wave propagation due to the ionosphere. In this experiment antennas should be placed sufficiently apart from each other (not less than 5-10 meters), to avoid mutual interference between short wave and ultra-short wave signals. Antennas should be oriented in the north south direction (R. 13).

SECTION 13-SUBMISSION OF DATA

The Radio Engineering and Electronics Institute of the U. S. S. R. Academy of Sciences has been designated as a central collecting and processing point for data received from the sputniks. All radio amateurs participating in the observation program have been asked to send descriptions of radio equipment used along with data and magnetic tapes of the recorded signals to the above institute at No. 11 Mokhavaya Street, K9, Moskva (R. 12).

In order to obtain maximum utility from the observations and to simplify processing and analysis of observations, the participants are requested to submit their data in accordance with the following outline:

A. Place, date, and time of observation. Time should include beginning of reception, termination of reception, and moment of greatest signal volume, all recorded in terms of Moscow time.

B. How time was recorded (by ordinary watches, by calibrated watches, or by radio time signals).

C. Frequencies of received signals.

D. Reception characteristics (fading and disappearance of signals).

E. Rate of key modulation.

F. Time of passage thru equisignal zone (when a direction finder is used) or time of maximal passing (when Doppler effect is used).

G. Meteorological conditions at the time of reception (cloudiness, rainfall, etc.).

H. Type of receiving equipment (detailed description).

I. Type of antenna and location of its installation (surrounding objects). J. Type of tape recorder and speed of recording tape (in mm/sec.).

K. Last name, first name and patronymic, radio amateur rating, and exact address of observer (R. 12).

It also requested that after termination of signal reception a brief message concerning location of reception, date, time (Moscow time), and signal frequency be immediately sent by wire to following cable address: Moskva-Sputnik (R. 12).

SECTION 14-VISUAL OBSERVATION PROGRAM

Observation of the sputniks is also carried out systematically by 66 visual observation stations and two observatories in the U. S. S. R.. To this number should be added some 30 foreign observatories. In November 1957 a network of visual observation stations was being built in Soviet satellite countries. In addition thousands of amateur observers are participating in the program. In the U. S. S. R. amateur astronomers have a large amount of high-quality wideangle telescopes specially built for this purpose. Observation stations have equipment for determination of satellite position at a given time. This equipment permits optical stations to fix bearings to an accuracy of one degree and to fix time to an accuracy of less than one second. Each of the optical stations in the U. S. S. R. also maintains one or two "optical barriers" which consist of telescopes situated on the meridian capable of traversing along the vertical circle perpendicular to the visible orbit of the satellite. In addition the satellite is located by a method based on "local time rule." The satellite orbit does not participate in the daily rotation of the earth and the satellite itself passes over the given latitude in local sidereal time which slowly changes during the rotation of the orbit in absolute space around the earth axis because of deviation of the gravitational field (R. 15, 20).

SECTION 15-FUTURE PLANS: POWER SUPPLY

Having succeeded with their first two satellites, Soviet scientists and engineers are looking forward to future projects. Their press is full of plans for trips to the moon, Mars, and other planets. Their attention is often turned to specific problems such as development of remote-controlled equipment for exploration of the surface of the moon, calculation of rocket trajectories, and use of photonic propulsion in space.

The future development of artificial satellites of the earth will to a considerable extent, depend upon the successful solution of the problem of power supply for uses other than propulsion. The most obvious primary source in this respect is, of course, solar energy. Future satellites will, therefore, have their electric storage batteries recharged with solar energy, the conversion agent being based upon either photo- or thermo-electric principles. Incidentally, this method has not yet been used in the first Soviet sputnik. Thermonuclear energy sources are not being considered feasible for artificial satellites at the present time (R. 9, 38).

Photoelectric generators consist of a flat aluminum plate coated with a thin layer of silicon. One sq. meter of such a plate generates up to 50 watts of electric power. Since the plate must face the sun, it will have a special solar tracking device maintaining the plane of the generator at right angles to the solar rays. DC to AC conversion can be accomplished with semiconductor devices operating at 90% efficiency.

At the present time, photoelectric generators are in experimental stage of development. One of the test models was recently shown at the exhibit of the Academy of Sciences; its efficiency, however, is only 5%. The photoelectric cell, weighing 20 grams, generates a current of 50 milliamperes at 2.5 volts. At the exhibit, this generator operated on light from electric lamps and powered a miniature electric motor. Silicon photoelectric generators break down, however, after prolonged exposure to sunlight, and better materials should be developed. Thermoelectric generators are based on the thermocouple principle. A battery of thermocouples is heated by convex mirrors. A generator weighing 110-115/kg. can supply power of about 100 watts (R. 38).

Another source of solar energy derived from molecular dissociation at high altitudes. Solar radiant energy at elevations of 30-40 km. is 10 times as high as on the surface. A small part of this energy is reflected by the atmosphere which, however, absorbs the bulk. The reason that the temperature of the atmosphere does not rise several thousand degrees is that solar energy is expended on breaking down, splitting, and dissociation of gas molecules. Molecules of nitrogen, oxygen, and other components of the atmosphere, are broken down into atoms. At night, the atoms reform into molecules and gradually release the energy which was used in their dissociation. Each kilogram of atomic oxygen 25484-58-pt. 2——11

as it reforms into molecular oxygen liberates 3,700 megacalories of heat. By means of certain inhibitors which retard the formation of molecular gas, compressed gases of the atmosphere can be maintained in atomic state in cylinders. This process can be reversed by means of catalysts which accelerate the formation of molecules a thousandfold and release vast amounts of energy. These catalysts were discovered only recently in the 1950's. It is assumed that in the near future this type of solar fuel will become available by compressing atmosphere in stations situated at 30-40 km. altitudes (R. 34).

SECTION 16-FUTURE PLANS: PROPULSION

The future development of space travel cannot rely upon chemical fuel because of its limitations. Dr. J. Gadomski of Poland, wrote in the latter half of 1957 that chemical fuels at best can launch a 50-kg. satellite to a height of 1,000 km. Although the subsequent sputnik launchings cast a doubt upon this statement, it is obvious that further space research must turn to other, unconventional forms of propellants. The ultimate space vehicle, frequently discussed in the Soviet popular scientific press, seems to be the "photonic rocket." According to the above Dr. Gadomski, chemical fuel can produce exhaust gas velocities of up to 3.5 km./sec. Atomic energy can boost this speed up to tens of thousands of km./sec. The real promise of space travel, however, is offered by the photonic rocket powered by a nuclear "lamp", as suggested by Sanger of the Nuclear Fuel Research Institute in Stuttgart. The photonic rocket consists of an accelerator of particles, an accelerator of anti-particles, fuel storage, and reflector in whose focus the particles and antiparticles annihilate each other producing photons (R. 22).

Prof. G. I. Babat, an industrial electrical specialist and author of popular scientific books, implies that photonic propulsion may be realized in the next 40 years. Photonic rockets, according to Babat, will depend on a stream of electromagnetic quanta reflected from the walls of the reaction nozzle. The difficulty inherent in this concept is the fact that even ideal reflectors absorb some fraction of the incident radiant energy. The magnitude and intensity of the photon stream required to propel a rocket is so great that the mirror would be vaporized in a fraction of a second if light of the visible spectrum were to be used. However, this difficulty can be circumvented by the use of centimeter waves of the electromagnetic spectrum. The lower energy quanta of centimeter waves are absorbed by mirror surfaces to such a small extent that it becomes possible to use them for propulsion of photonic rockets (R. 34).

SECTION 17-FUTURE LAUNCHING AND REENTRY METHODS

According to N. A. Varvarov, Chairman of the Astronautics Section of the Central Aeroclub of the U. S. S. R., the launching of an artificial satellite of the earth could be accomplished as follows: The launching vehicle would comprise a carrier aircraft, an accelerating aircraft, and a final stage rocket in that order. Each succeeding vehicle of that order would be carried piggy-back fashion on the preceding vehicle. The carrier aircraft would carry the system to a certain altitude whence, having released the accelerating aircraft with the rocket, it would return to earth. The accelerating aircraft would continue to gain altitude, release the rocket, and also return to earth. The rocket would place the satellite directly in its orbit. During each state, power would be supplied by the carrying vehicle only (R. 6).

According to another method, turbojet engines suspended under the large wings of the carrier rocket may be used for the takeoff and the subsequent flight through the denser layers of the atmosphere. After the altitude of 20-25 km. and speed of about 2,000 km./hr. have been reached, the turbojet engines will be jettisoned, the next stage of propulsion being taken over by more economical for these speeds ramjet engines.. These will lift the carrier rocket to the altitude of 35-40 km., where it will have a speed of about 5,000 km./hr. At this point, the ramjet engines will fall off together with the no longer necessary wings. Further stages of the flight will be carried out under the power of liquid-fuel rocket engines of the carrier rocket which may be of a single- or multi-stage design.

These methods of satellite launching can be used not only in conjunction with current energy sources, liquid fuels, but also when atomic engines will be available (R. 6).

The descent of the satellite and recovery of the results of observations (exposed photographic film) are possible, although this requires additional equipment. According to one project, the third stage of the rocket carries a collapsed sphere made of thin metal insulated by several layers of protective coatings. The exposed film cartridge is placed inside the sphere which is then filled with bottled helium. The film cartridge is also protected from heat by special coating. The falling speed is retarded by a small braking rocket also installed in the third stage carrying instruments and the remaining apparatus. The inflated sphere descends like a parachute and reaches the earth's surface intact. Another project provides for a satellite with wings to make it glide safely to earth. To increase the visibility of the satellite, it was suggested that it emit sodium vapor which shines with bright light when exposed to sunlight. (R. 31).

SECTION 18-FUTURE PLANS: MOTION IN SPACE

Soviet authors are widely discussing space travel based on the utilization of the gravitational fields of the planets and the ballistic motion of the space ship. A project making a direct use of this idea has been credited to a Leningrad scientist, G. Chebotarev, who proposed to send a noncontrolled ballistic rocket to the moon, claiming that this will require merely 16 tons of fuel instead of the expected hundreds of tons. The trajectory for such a ship has been computed by the Institute of Theoretical Astronomy of the Academy of Science of the U. S. S. R. which estimated that the ship could be brought to round the moon at a sufficiently close distance and return to earth. According to calculations, the rocket without fuel, i. e., the apparatus and instruments enclosed in a spherical shell, should weight 50-100 kg. (R. 28, 30).

The Institute, located on Vasil'yevskiy Island in Leningrad, is the world's only specialized institution devoted to the detailed study of the motion of celestial bodies. Using large automatic computers, the Institute analyzes the motions of the earth, moon, and other planets of the Solar system and those of the largest and brightest stars. These computations serve as a basis for the publication of special astronomical calendars (astronomical ephemerides) specifying the position of celestial bodies at any time.

The first trajectory of a ballistic rocket, which the Institute succeeded in computing, would bring the rocket in five days to a distance of less than 30,000 km. from the moon and return it to earth. The maximum distance of the rocket from the earth reaches 416,000 km. Since the moon is 384,000 km. away from the earth, the rocket in this trajectory can round the moon. At this point, the speed of the rocket will decrease almost to zero, leaving it in the vicinity of the moon for over two days during which time it can investigate the hemisphere of the moon invisible from the earth, by means of its automatic instruments. The return flight to the earth will also take about five days. The landing will be accomplished by parachute or a glider device.

Uncontrolled (ballistic) interplanetary ship can obviously travel in space without the expenditure of fuel along more complex trajectories, for example to Mars and back. The Institute is computing a Mars trajectory for a ballistic rocket (R. 30).

Another organization engaged in work of this type has been the Mathematical Institute of the Academy of Sciences of the USSR which during the period 1953-1955 carried out a systematic investigation of a cycle of problems involving the theory of flight to the moon. These problems involved the form and classification of trajectories along the ballistic section of the path, possible trajectories circling the moon with return to earth, minimum intial speeds required to reach the moon, and the effect the scattering of initial data has on the various trajectories. The Institute performed a series of numerical computations using a high-speed electronic digital computer (R. 25).

Plans for a trip to Mars, claimed to be underway in the Soviet Union and abroad, specify ten space ships of 1,700 tons each to be launched from an intermediate satellite station. The ships are to be launched from the circular orbit of the station into an orbit leading to Mars using the gravitational force of the sun instead of fuel. The trip there will take 256 days. The crew will have to wait on Mars until a convenient mutual position of Mars and earth will allow for starting the return flight. The waiting period is 440 earth days. The entire trip will take 952 days. It is thought that flights of this type will be possible by the end of this century (R. 2).

SECTION 19-SOVIET SPACE TIMETABLE

At the present time, there is a practical basis for a discussion of a device capable of reaching the moon. Further development and improvement of artificial satellites should, at first, increase their dimensions and weight to accommodate more powerful energy sources for communications and scientific instruments. To increase the effectiveness of observations, the satellite should have a capability for assuming definite attitudes in space. Consequently, it should be provided with facilities for automatic control of its motion.

In the next stage of development, radio-controlled satellites will be created with motors and fuel supply. By switching the automatic motor on or off, the rocket will be transferred from one orbit to another. It should also be desirable to have automatic devices capable of braking the rocket at the entry into the denser layers of the atmosphere where it would be allowed to glide. This would secure the return of the satellite to the earth, increasing the value of scientific observations.

When the rockets will have well controllable engines, when crews of pilots trained in withstanding weightlessness will be available, when good space suits will be produced, then man will appear in the rockets and satellites. Manned rocket-satellites will be able to change trajectories and approach each other. Men will emerge on the surface of their ships, making it possible to create large cosmic stations orbiting around the earth, described so long ago by K. E. Tsiolkovskiy. The cosmic stations may be used for the assembly of interplanetary shins.

The interplanetary space, however, will be first probed by radio-controlled ships. In particular, it is assumed that the first flights to the moon will be accomplished by pilotless rockets equipped with automatic devices for photographing the invisible side of the moon and for the transmission of the images to the earth. It is also possible to build various robot devices capable of moving from the space ships to the moon surface to carry out observations and to transmit the results to the earth (R. 45).

An outline of the approximate timetable of space conquest was given by V. V. Dobronravov, a committee chairman of the Astronautics Section. The future of astronautics can thus be divided into three periods: The first, to be marked by the launching of radio-controlled pilotless rockets to an altitude of 300-400 km., capable of realization at the present time. The second period will witness the building of a manned satellite of the earth, about the year 1975, and will terminate in a flight around the moon without landing (1980-1990). The first space flight to the moon with landing and return to earth will usher in the third period around the year 2000. Dobronravov regards this as a very conservative estimate (R. 21a).

Although Dobronravov's article was written in 1954, his target date of 1975 was still closely approximated three years later, in a 1957 Soviet popular scientific article. This time, predicting the first manned flight to the moon for 1974, the article states that the rocket will be powered by the thrust of water heated by an atomic reactor (R. 28).

Academician A. A. Blagonravov claims that the U. S. S. R. now has a rocket which is capable of reaching the moon. However, for the moment, such a rocket will not be able to return to earth (R. 33).

SECTION 20-GENERAL RESEARCH PROJECTS

One of the important aspects of space travel development is the opportunity it affords for scientific research which would be extremely difficult or impossible within the limits of the lower atmosphere. A portion of the space effort is thus related to the program of the International Geophysical Year. During the IGY, the U. S. S. R. will launch over 100 rockets for extensive sonding the upper layers of the atmosphere not only in central latitudes but also in the Arctic and Antarctic. The rockets will be expected to reach altitudes of several hundred km. Launchings will be carried out on "world days" and during periods of special solar activity. The launching pattern is as follows: From the Arctic and Franz-Joseph Land-25 rockets in 1958; from the mean latitudes of the U. S. S. R.-30 in 1957; from the Antarctic (mainly from the area of Mirnyy Station)-30 in 1957 and 1958. A series of artificial satellites of the earth will be launched, involving a wide scientific program. To clarify special questions. the use of anthropoid monkeys, rodents, mollusks, and insects will be needed.