Luna - Exploring the Moon
2015 Jan 26
Monday, Day 26
Selected Luna Missions:
A different view from Ian Ridpath
Summarised by Don P Mitchell
The Mission of Luna 1
Luna 1 was a hermetically sealed sphere with external sensors to detect radiation and magnetic fields. The boom holding the magnetometer away from the body of the spacecraft projects towards the top right with its end out of view. The other projections are radio antennae.
It used chemical batteries for electrical power which gave out the day after it missed the Moon when they reached their design limit.
Luna 1 Described by Soviet Engineers
The last stage of the space rocket is a guided rocket fastened to the stage immediately preceding it by means of an adaptor. Control of the rocket is effected by an automatic system which keeps the rocket moving along the set path and ensures the set speed when the engine has completed its duty. The last stage, after the stock of fuel has been consumed, weighs 1,472 kilogrammes.
Besides the devices to ensure the normal flight of the last stage of the rocket, its body houses:
A hermetically-sealed separable container with scientific and radio-technical instruments,
Two transmitters equipped with aerials working on frequencies of 19.997 and 19.995 megacycles,
A counter of cosmic rays,
A radio system with the aid of which the flight trajectory is determined and its further movement is forecast,
Equipment for producing an artificial sodium cloud.
The container is located in the upper part of the last stage of the rocket and is protected from overheating when the rocket passes through the dense layers of the atmosphere, by a cone which is then discarded.
The container consists of two spherical half-shells tightly connected by frames with packing made of special rubber. Located on one of the half-shells are four rods of the antennae of the radio transmitter operating on a frequency of 183.6 megacycles. The antennae are fastened on to the body symmetrically relative to the hollow aluminium pin, at the end of which is an instrument for measuring the magnetic field of the Earth and for detecting the Moon's magnetic field if it has one. Up to the time the protective cone is discarded the antennae are folded up and fastened on to the pin by a magnet, and after the cone is discarded the antennae open up. Located on the same half-shell are two proton traps for finding out the gas component of interplanetary matter, and two piezo-electric pick-ups for the study of meteoric particles.
The half-shells of the container are made of a special aluminium-magnesium alloy. On the frame of the lower half-shell an instrument holder of tubular design made of a magnesium alloy is fastened and the instruments of the container are placed on it.
The following equipment is housed in the container:
Equipment for radio control of the trajectory of the rocket's movement consisting of a transmitter operating on a frequency of 183.6 megacycles and a block of receivers,
A radio transmitter operating on a frequency of 19.993 megacycles,
A telemetering unit designed for transmitting by radio to the Earth measurement data and data on the temperature and pressure in the container,
Instruments for studying the gases contained in interplanetary matter and the corpuscular radiation of the Sun,
Equipment for measuring the Earth's magnetic field and detecting the magnetic field of the Moon, if there is one,
Instruments for studying meteoric particles,
Instruments for registering heavy nuclei in primary cosmic radiation,
Equipment for registering the intensity of cosmic rays and the variations of this intensity, and for recording photons in cosmic radiation.
The radio and scientific equipment housed in the container get their electricity from silver-zinc and mercury oxide batteries placed on the container's instrument frame.
The container is filled with gas at a pressure of 1.3 atmospheres. Its design ensures high pressurisation inside. The temperature of the gas in the container is maintained within the set limits (approximately 20 degrees Celsius); this is accomplished by imparting to the container's shell certain co-efficients of reflection and radiation through special treatment of the shell. In addition, a system ensuring forced circulation of the gas is installed in the container, and the circulating gas draws off the heat from the instruments and transfers it to the shell, which thus serves as a radiator.
The container detaches itself from the last stage of the rocket when the engine of the last stage has done its work.
The separation of the container is necessary to ensure its thermal regime. Located in the container are instruments which generate a lot of heat, and the heat regime, as has been pointed out before, is ensured by maintaining a certain balance between the heat emitted by the container's shell and the heat received by the shell from the Sun.
The detaching of the container ensures normal functioning of the container's aerials and the instruments for measuring the Earth's magnetic field, and for finding out whether the Moon has one. As a result of the separation of the container the magnetic influences of the rocket's metallic structure are eliminated from the readings of the magneto-meter.
The combined weight of the scientific and measuring equipment plus the container and the source of power located in the last stage of the rocket is 361.3 kilogrammes.
To mark the building in the USSR of the world's first space rocket, now an artificial planet of the solar system, two pennants with the coat of arms of the Soviet Union were placed in the rocket's container.
One pennant is a thin metal strip with the inscription "Union of Soviet Socialist Republics" on one side and the coat of arms of the Soviet Union and the inscription "January 1959 January" on the other. The inscriptions were made by a special photochemical method, ensuring long preservation.
The other pennant is of special shape, symbolising the artificial planet, and the surface is covered with pentagonal elements of special stainless steel. chased on one side of each element is the inscription "USSR, January 1959," and on the other the coat of arms of the Soviet Union and the inscription "USSR".
After Luna 1 passed by the Moon 1959 Jan 4, it went into orbit about the Sun and became the first artificial planet. Its orbit carries it between 146 million kilometres and 197 million kilometres from the Sun, taking 450 days to complete a circuit.
The first stage of the rocket consists of a central core booster with a four-chambered liquid propellant rocket engine, using liquid oxygen and kerosene. It is surrounded by four more boosters with similar engines. These boosters are jettisoned when the propellant is exhausted, and stage two consists of the central booster firing alone. The Vostok rocket was created by adding a third stage to the Sputnik (R-7) rocket.
Luna 1 Statistics:
Launch Vehicle: Vostok
Launching Technique: Direct ascent
Mass: 361.3 kilogrammes (1,472 kilogrammes including the final-stage rocket)
Diameter: 0.9 metres
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