Kamchatka to the northeast reaches the ocean as a vast lowland with solitary volcanic hills scattered over it. Here lies the area of the fall of warheads of intercontinental missiles. The fall is interesting, so it is observed from several measuring points located around the battlefield. Combat work is stressful, but there are moments that carry their hidden laughter, like the hidden drama in Hokusai's prints.
Once at the 14th measuring point, or IP-14, contact with the antenna disappeared. Although, let's first clarify what we are talking about. Measuring points are small military towns. Their working heart is brought to the very edge or a few hundred meters from the town. A two-story technical building, to which all measurements of the flight of warheads flock, and on its flat roof are huge precision cameras.
They capture the emergence and passage of bright lights in a sophisticated way by taking optical measurements of the trajectories of warheads. An even greater flow of information is carried by radio waves. Some points have radar, others have radio systems. But the main part of on-air data is telemetry.
The ancient Greeks were undoubtedly great inventors. They invented such a huge mass of their verbal roots that still live on all continents and in different languages, areas and directions. "Tele" in their language meant "far", "at a distance", "across a distance", "afar"; well, "metreo" - "measure." Measurements at a distance, measurements through a distance began to be called telemetry.
But what if, for example, we lay down at some distance with a sniper rifle and work with the scope? Knowing the approximate distance to the observed line, let's look through the eyepiece at the sighting risks in the field of view of the usual sight of the PSO-1 optical sniper. Risks cut off segments of one thousandth of the removal. The size of an object that fits exactly in one segment between adjacent risks of the sight is one thousandth of the distance to it. If the object occupies two lines, its size is two thousandths of the distance to the object. Seeing how many segments the observed object occupies, and knowing the approximate distance, we will measure its size. Is this telemetry? No, this is not telemetry.
And if you simply measure the phase of the earth's satellite on a moonlit night - is it full, in the first quarter, or in the last? The moon is far away, we measure its phase through a distance of 380 thousand kilometers - it seems quite far away.Even if you look through a telescope? No, this is not telemetry either, as it requires another feature. Organized transfer of data from the object, through this very "far".
A device must operate on board, transmitting measurement data from there to the receiving part. Then it will be telemetry.
Data can be transmitted over a transmission channel of any nature. If through a cable with copper wires inside, you get cable telemetry. When a space rocket is at the start, a cable-mast must be connected to it, in which a lot of all kinds of wires are laid, connecting the rocket with the rest of the ground-based equipment and the command center. Many wires are combined into bundles - cables - which is why it is called a cable-mast. At the top, the cable mast is connected to the rocket through connectors. A few seconds before the start, the cable mast is disconnected and deflected to the side, without interfering with the rise of the rocket.
The cables transmit data from a large number of measurements and registrations performed inside the rocket. The temperature of the fuel and oxidizer at different heights of the tanks, the pressure inside the fuel tanks, inside the non-fuel tanks (there are a lot of all kinds of tanks and cylinders in the rocket with the most different contents), the pressure in the pipelines and highways, the voltage in the on-board network and devices, the state of different valves, positions switches and the like. By means of cable telemetry, these data are taken out of the rocket and go far beyond the launch pad, where they work with them at a safe distance and in full technical equipment with all kinds of devices for processing this data.
Once, from Kapustin Yar, the Soviet winged apparatus "BOR" (unmanned orbital rocket plane) was launched into space, on which the tasks for the creation of "Buran" were worked out. And during the preparation of the launch from the rocket, at the top of which the BOR was installed under the fairing, information ceased to flow. During the search for the cause, it turned out that the cable laid in the cable mast failed. As a result, it had to be replaced, for which for almost a week the failed cable was cut out with chisels from the recesses in the mast filled with an epoxy fixing compound, where the cables were laid. After long and many efforts, the cable was replaced and preparations for the launch continued.
Data can also be transmitted by radio waves. Then it's radio telemetry. In this type of telemetry, data from a sensor that measures something on board is fed into an onboard radio transmitter and emitted by radio waves. After passing through space, the radio waves are picked up by the receiver at the measuring point. The transmitter on board the warhead together with the receiver at the measuring point and the space between them constitute a radio channel - a vehicle for information. After leaving it, jumping from the radio channel from the receiver to the cable, the data goes to the recording equipment for recording and further processing.
Galley or telemetry galley (optional)
Now it's time to move on to the case itself, but let me leave a clarification in the middle of the story. Telemetry is a rich thing.This is the mechanism and process of transferring large amounts of data, which is why the loss of telemetry is so devastating to the results of the launch. You can skip this part and move on to the next, and we will take a short look at the galley. In its most general form, it is arranged something like this.
It all starts with the sensor: it is the very first in the entire further chain. The sensor comes into contact with the measured value - pressure, temperature, illumination, acceleration, voltage and other measured parameters. It emits an electrical signal corresponding to the measured value. A sensor is an eye that receives light and creates a nerve signal from it. The electrical signal of the sensor cannot be immediately pushed as it is into the radio transmitter for transmission. First, the sensor signal must be prepared, converted into the form required for transmission.
With great speed, the signal is cut into small pieces of a certain size, so as not to lose the information it carries. The finely chopped signal is combined with other similarly chopped signals from other sensors - a great many.
The resulting okroshka, however, is not mixed as usual. The vinaigrette is not good here. On the contrary, the pieces of signals are neatly and evenly laid out in a strictly defined order in a beautiful slender mosaic on a large rectangular tray called a telemetry frame. When unfolding this mosaic, the chopped sensor signals generously alternate with a whole handful of any other technological signals - not of a measuring nature, not from sensors. For example, split markers, time markers, the number of this telemetry frame, an end-of-line mark, an end-of-frame mark, and so on.
These are already the own seasonings of the coca - the on-board chef preparing the dish. With such additives of technological signals, he generously flavors the measuring crumb, not only for the convenience of preparation and strict preservation of the dish, but also for its reliable analysis later, on the ground.
Finally, the tray of the telemetric frame turned out to be smooth and correct for a feast for the eyes. Everything is laid out in beautiful rows, each piece of each signal is strictly in its place, according to all the specified rules. The data is arranged in the same repeating order, rhyming strictly according to the telemetric frame format. Now the telemetry chef who laid out this tray is giving it to a radio transmitting baker to bake.
The baker's business is the transmission of radio waves. Squinting, he slips a tray of telemetry footage into a special oven full of high-frequency electricity. High-frequency electrical vibrations arise in an organized manner in a special firebox and rush to the telemetric frame tray. Closely and carefully touching this frame, with each of its elements, grain by grain, piece by piece, row by row, line by line, high-frequency electrical vibrations accurately imprint the entire telemetric frame down to the last millimeter. Dressed in coding and modulation, they go to the antenna of the radio transmitter.
The antenna converts the received electrical vibrations with the telemetric frame imprinted on them into winged radio waves. Precisely preserving the imprint of the telemetric frame, radio waves fly out through the chimney of the emitter, breaking out into the freedom of open space.
Instantly they rushed through the void of space and the atmosphere and fell into the vast expanses of the planet. Everywhere and everywhere. At the same time, on the landscapes in which there are receiving antennas waiting for them. The ground part of telemetry begins there.
The radio waves that fell on the ground hit the entrance of a special antenna - very sensitive to receive a radio signal from a long distance. It catches the radio signal and sends it in the form of waves along a long reliable waveguide hose to the room where the receiver is located. This is a control room filled with receiving and recording equipment. Here, a story similar to the onboard story takes place. At the receiver, the sensor converts the waves into electrical signals. With the imprint of the telemetric frame accurately preserved on itself, of course. A pencil is tied to the electrical signal, and the signal draws its own drawing, the whole picture of the telemetric frame - exactly, grain by grain, piece by piece. And here it is, on the table in the control room, there is a fresh, accurately drawn telemetry frame. The one that was carried through space by radio waves and which was made by the cook there, on the far side.
Now you need to parse this telemetric frame back and decompose the shredded data of different sensors from the frame separately - from each sensor into its own line. This is not difficult: the very own service seasonings help, which the telemetry cook on board generously flavored with the measuring crumb. Now, they can be easily disassembled, sorted and separated from the pieces of some signals from others. And in each separate laid out line, successive pieces of measurement data of this sensor are added. Lay them out along the timeline, one after the other, in the order of occurrence and arrival - and the record was formed. Before us are the successive values of the temperature or pressure that the selected sensor measured during this time, there, far, thousands of kilometers from here, aboard a rapidly flying warhead lost in space.
It remains to add that telemetry frames are created and pushed into the radio transmission oven quickly, many times a second. A telemetry frame can contain information from several tens or hundreds of sensors. The stream of measurement results of any one quantity generated by one sensor is called a channel. Roughly speaking, each sensor is a measurement channel. And the whole kitchen that we looked into, including those places where we did not look, is called a radio telemetry system. Multichannel telemetry systems are different. For objects with simpler channels, there may be twenty-four, or fifty, or a hundred, or two. On the Apollo ships, telemetry contained fifteen hundred channels; on the Shuttle, the telemetry system contained 12 thousand channels.And measure each value sometimes several thousand times per second. And thousands of times per second new telemetric frames fly into space.
Chamomile, or Mushroom with honeycomb
On earth, everything looks unusual and technically beautiful and is called entirely precious names. At the point there was an antenna-feeder device AFU "Zhemchug", it is also in common parlance - "chamomile". Not far from the end of the technical building, looking towards the rearing power of Shiveluch, on a square base stood a two-meter-high vertical concrete carrot, with a void inside and a gray iron door. She was the base from another system - a square flat "Emerald". Above this conical stalagmite towered a strange and picturesque creation of human hands. This unit was several meters in size and resembled a daisy with clear hexagonal petals carved from the cap of a boletus mushroom. On the petals, the caps of the thin mesh honeycombs went forward.
The symbiosis of mushrooms, flowers and bees is outwardly incomprehensible. Behind the "mushroom cap" there are "roots" that are spread out in space - polygons of wind compensators spaced apart on tubular brackets. These six "burdocks" of different sizes and shapes compensate for the unfolding effect of the wind on the "mushroom cap", creating their own turning moment in the wind, which balances the unfolding moment of the "cap". Standing out against the background of the greenery of the forest with a light gray color, this thing is covered in front with a radio-transparent varnish. It receives radio waves of the meter and decimeter range. Inside each "honeycomb" on the mushroom petal, including the central one, completely hidden by the cap, there are two vibrators located crosswise. They perceive the fluctuations of the electric field of the radio wave coming from the warhead: one in the vertical plane, the other in the horizontal plane, or in the vertical and horizontal polarization.
The entire sensitivity of the antenna is collected in a narrow needle and directed exactly forward, immediately and sharply falling with a slight deviation of the direction of reception to the side.
In other words, its directional pattern resembles a sword. And with this sword, the antenna can make contact with an object in the sky from a very long distance. Like a sword of great length, one and a half thousand kilometers. But as soon as the object moves a little to the side of the point, or the sword deviates from the object, and the sword misses, the connection with the object is lost. Therefore, in the process of receiving a signal, the "Pearl" must be aimed at its target warhead (which is assigned to it for targeted guidance) with maximum accuracy. Such guidance is carried out throughout the entire flight of the warhead.
When the warhead is still flying far in space, it practically does not move across the sky, simply shortening the distance to the measuring point. The "Pearl" aimed at her seems motionless. But with the appearance of a gradual displacement of warheads in the sky, he also noticeably changes the angle of his gaze, slowly turns.When the warhead visually accelerates in rapid motion obliquely across the sky, the gray chamomile mushroom with the same speed, unexpected for its size, turns around behind it, without releasing the warhead from accurate aiming. The mushroom is directed according to a program specially calculated by ballistics at the place where the warhead should be at that second. The vibrators under the mushroom head receive the signal - each in its own polarization - and transmit it to the waveguides.
Signal reception is always expected with intense attention, like a bite on the morning surface. After the launch of the rocket at the receiving site, there is no information about what is happening to it above the Earth. How did the first and second booster stages work? Whether the combat stage separated, how it worked, whether the warheads were divorced. Sometimes it happens that the rocket left the start, but nothing came to Kamchatka. Whether the deployed warheads go to the area of the fall, or an undiluted lump falls, or there is nothing at all in the sky.
Therefore, the appearance of a warhead signal in the sky means that the disengagement process has taken place, the warheads are flying and have already reached the antenna's sensitivity zone. The signal does not appear immediately. It first appears in one or the other polarization - it is received "along one or the other trunk", speaking in the language of telemetrists. Signal drops turn into short interruptions, become less frequent, and soon there is a stable signal reception on both trunks. The news of the reception of the signal is also brought to the stations of the optical means, so that the phototheodolites on the roof are prepared for the appearance of a glow in two to three minutes.
From the cement pedestal with a vertical carrot to the end of the technical building, there was a flat concrete trench, laid in the ground, closed from above with steel tires - payols. In the trench lay thick hoses, braided from the outside with a dense metal wire braid. These were feeders - channels for waves received by Zhemchug. Therefore, the whole system was called the AFU "Pearl" - an antenna-feeder device. Through the feeder-waveguides, the wave ran inside the building and entered the control room with receiving and recording equipment, where it was converted into electrical signals. Feeders must reliably protect their wave channel from the penetration of any radio-electric interference into it. Feeder-to-antenna connections are tight and look like big, heavy, fist-sized connectors that use gold plating to keep the contact clean.
Dramatic Contact, or the Story of a Resourceful Soldier
“Once, in a cold winter time …” the head flew, as it was customary here. So far, far away, over the Siberian expanse, in about twelve minutes. And then it began: contact with the antenna stopped, disappeared. And time was running out at all.
Only a few minutes remained at the disposal of the station's calculation before the start of receiving a signal from a warhead already flying over the west of Chukotka. The solution had to be found and accepted immediately. Assumption: water got into the gold-plated contacts (penetrated, settled, condensed from loose screwing, but it is not known how). Which froze, expanded and pushed back the contact surfaces.Or simply lay down with a thin film of insulating dielectric ice. There is only one way to urgently remove water: immediately rinse the contacts with pure alcohol, double rectified, that is, double distilled alcohol. Pure alcohol is extremely hygroscopic and absorbs water immediately. Therefore, it is often used for dehumidification. You can't waste a second. After all, every second brought the warhead five and a half kilometers closer to the start of receiving its telemetry signal.
With quick movements, they opened the containers with alcohol. The head of the station did not want to climb into the cold and poke around in the frozen connectors, and there was no need. For this, the fighters and the station operators are fully prepared and trained. The fighter-operator was handed a three-liter jar, generously filled above the middle with the purest alcohol, a tool and clean cleaning products. He was instructed to run to the base of the "Pearl" support pedestal, clean off the snow, lift the payola, unscrew the feeder connector and rinse it and the junction with the antenna alcohol from the can several times. Then reassemble the connector to its original state. Such an operation was provided by the operation manual and was a regular way to fix the problem.
And a wonderful, dramatic scene unfolded, quite suitable for the classic tragedies of Aeschylus. The actors occupy strictly outlined stage positions. In the cold winter sky, an invisible warhead, at a distance of two thousand kilometers, rapidly approaching with its telemetry signal. In the heated control room, the head of the station and the commander of the combat work are sweating, bitterly anticipating the scattering after the unsatisfactory assessment of the item on the basis of the results of combat work. Loss of telemetry is an inevitable deuce.
And in the corridor of the building, on the way to the emergency exit and the antenna with its contacts, a fighter frantically rushes about with a large can of alcohol. Also instantly sweating from the intense work of thought, not knowing what to think of and where you can get a container right now in order to pour it into it from a can. The fourth character is time. It is spread all over the stage and, despite the weak and stable gravity of the Earth, for some reason it is slowly accelerating. And this acceleration is felt by all participants in the action.
The result of the silent dramatic scene was a general victory. The fighter managed to disconnect the connectors, rinse them several times with alcohol, reconnect them and close them with a liner. The lost connection with the antenna was restored. She left, the bitterness that had already rolled off the faces of the commanders flew away. The long exhale and the cruel urge to smoke merged into a single wave of inner relief. Reception of the telemetry signal from the warhead began at the expected time. He quickly filled both trunks with himself, the reception became stable, without loss of information, and went his usual way. The soldier returned to the building with a completely empty can and a calm, internally satisfied expression on his face. As if he knew some good secret. There was no longer any trace of the despair he had experienced. On the contrary, as if a spark of a winner played in his eyes.