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DISCOVERER

DISCOVERER 1 to 38 - CAPSULE discoverer - WINNING PHOTOGRAPHY RECOGNITION

DISCOVERER

Discoverer, together with the equipment for monitoring the work, was an integral part of Agene A. The fuel was filled with fuel, the weight had a mass of 3850 kg and down to about 780 kg. The rocket engine Agene would start working 120 km over the Earth after the first sea level detachment collapses. After entering the elliptical orbit, the engine is switched off, and Agena turns to 180 degrees to turn the top backward. Special sensors are taken care of to maintain a proper trajectory. During the voyage from Vandenberg to the track, the missile is accompanied by two ships set 2600 km south of the base. After crossing the Antarctic, Discoverer crossed the Indian Ocean and the Asian mainland, reached the North Pole, and then reached the Earth station Kodiak in Alaska, the first point to which the flight control could come in touch with him.

Choosing the right path Discoverer is limited to some immutable conditions. Satellites have had to use a polar orbit, 90 degrees inclined to the equator, because their traces have to cross the goals in Asia and the Far East, and also to fly above the Pacific Ocean where the planes caught capsule for return to Earth. In case of failure, the satellite descends to the water and can not find it patrol boats; like out of the question when you fall on the Asian mainland.

US Aviation Aircraft must grab capsules for a limited number of days, and this also limits the choice of trajectory, as the satellite every day needs to cross the Pacific Ocean. It was also worth considering the camera's features - which satellite was at a higher altitude, the resolution was weaker. As it turned out, paths with a period of 92 minutes were most appropriate for all purposes.

Earth rotates from west to east, and a tour of the path with the patrol time of 90 minutes causes the mark satellites in the west; plane of the orbit is, of course, does not move, because the rotation of the planet does not affect it. That's why the other monitoring stations set up in New HampshireOn the east coast of the United States. The third is located near the town Kaena Point in Hawaii, and serves mainly to manage operations when the satellite is returned to Earth. Humans and equipment for finding a capsule are located in the nearby aerospace base Hickam. From this place in search of the satellite, they leave the planes C-119. When a moment arrives, Agena is leaning toward Earth for 60 degrees. After separating from the main part, a small rocket engine on the capsule returned to the atmosphere, reducing the speed for 1400 km / h. So sluggish, the capsule begins a long way to the ocean. The return signal is sent from the command center at Vandenberg base.

Shaped like a tattered turgue, a capsule to return to the atmosphere served as a pilot form of future thrilling heads on intercontinental ballistic missiles. As long as one of the Ames aerospace engineers did not realize that the best shape for returning to the Earth was not a splinter-bladed cone that produced extra air resistance, no one could construct a body that would return to the atmosphere. The temperature, created by converting kinetic energy into heat, simply poured all the known materials. Therefore, the capsule is designed to produce the highest resistance, so a shock wave is prevented from occurring in front of it, preventing the heat transfer to the metal mantle, thus lowering the temperature of the tolerable 1700 ° C. It has been so much recorded on Discoverer's capsule protected by ablative plastics that partially burned and cracked and referred to excessive heat energy. At the height of about 15 km the parachute was thrown away, and the rest of the heat shield was discharged with it, and the satellite began to slowly go down to the ocean. Following the capsule with a radar, the plane comes close to it and catches it with a special trapeze device. Satellites and his relaxed parachutes were pulled into a plane and returned to Hickam Base. 1961, the C-119 aircraft used during the first two years of the Discoverer program, replaced the model C-130. At the time of the satellite technology was still in its infancy, the operation represented a truly bold endeavor. But often published news about the activities of civil NASA, overshadow the achievements of the Ministry of Defense.

Let discoverer 1 begins quite normal 28. February 1959, but soon after it reached the intended orbit, the satellite escapes to ground control. This time Agena A was not wearing a return capsule, as opposed to next year discoverer 2, less than two months after that. Everything went smoothly until the human error had caused a drop down early, and the satellite was dropping somewhere in the north of Norway. The capsule was seen to fall easily on the ground, but extensive research did not produce fruit. In June, two more discoverers will be leaving Vandenberg, but none has reached the orbit. The fifth flight went on without difficulty until the moment of return, when the wrongly directed Agena sends the satellite deeper into space instead of back to Earth!

Partial success has been achieved and 19. August when Discoverer 6 performs all the foreseen tasks, but on return, a radio transmitter is dropped, and the capsule unexpected falls into the ocean. But these, at best, the half results, are just an introduction; follows a series of failures in the next six flights. Discoverer 7 he began to spin the fury; Discoverer 8 is due to problems in Thor carrier arrived in the wrong path; Discover 9 and 10 because of similar difficulties they did not even reach orbits; capsule discoverer 11 is lost in return; Discoverer 12, launched in June, 1960, also had no luck with the carrier.

And so, the US Air Force during 18 months launches Discoverer without success. Until that moment, no one capsule is not found - no one has to be honest and say that not one item, regardless of whether Soviet or American, not previously saved after returning from space - and hope for the realization of the planned date of implementation of the new satellite systems Samos all have less . But then comes the first success. Experts Air Force know that everything depends on the next year: Discoverer 13 full of special equipment for monitoring of the satellite. Even the capsule, in a technical sense only shell to return equipment (Satellite Recovery Vehicle, SRV), was equipped with control instruments, and hopes for future successful flights were made.

Wednesday was also coming, 10. August 1960, the historic day for the Air Force of the United States, as well as flights to the universe at all. As Thor rocket rocked in the sky, the monitoring stations controlled the operation of its drive and control systems. The worst of Discoverer's temptations were during the first few minutes of flight, since the vibrations are then the strongest, and every strain of material has been greatly increased. Thor and Agena flew more and soon arrived in the anticipated elliptical trajectory with the lowest point (perigee) of 258 km over Earth, and the highest (apogee) on 683 km of the planet. Everything is done exactly according to the plan and experts in the next few hours carefully monitor all satellite data. The next day, around 16 hours and 15 minutes per local Pacific time; a signal to return to Earth was sent. Agena, facing her back, leans against the planet, the capsule breaks down, a small rocket engine crashes into solid fuel and begins a long return to the far ocean. With a shaky atmosphere, glowing almost to the air, the satellite falls to a certain point in the ocean. The C-119 aircraft running around in vain searches for the radio signal capsule. Eventually they saw it, but it was already too low. The satellite falls into the sea. From the ship Haiti Victory chopper. The water-frog was jumping and swimming capsule to jump around the troubled waves. Ropes are tied to anchor and viewed in a helicopter lifted first object made by human hand, and returned from space. Exactly a week later, after a careful study of the capsule Discoverer 13 and data that are with him, arrived while he was in orbit, finishing preparing the next year. Launched from Vandenberg 18. August, Discoverer 14 returns to Earth a day later, starting back over Alaska. In the descent there were several aircraft C-119, ready to forestall this time the Navy. One among them was, right under the parachute at a height of 2600 m. He managed to catch and pull the hull. Discoverer 14 was a big boost morale of all employees in the program. Of the five missions initiated by the end of 1960. only two were completely successful; in one of them, Agena was not wearing a return capsule only infrared sensor devices intended to be incorporated into satellites Midas.

Discoverer 16 introduces a newspaper: it refers to the orbit Agena B, longer than the "Model" and higher carrying capacity. Discoverer satellite flight geometry forces back capsules during 17, 33, or 65. orbit. The first one who landed the Earth for two days was Discoverer 17 in November 1960, and only three weeks later, Discoverer 18 stay in the universe for three days. The program has met all planned plans, and experts have also learned how to coordinate complex spaceships. In addition, Discoverer's tried new technology ideas.

Next year, the take-off hour was really full, because in the universe the 17 satellite was out of the series, of which only seven were completely successful. The limited capabilities of the spacecraft at that time did not always yield the desired results, but that was enough for the success of military and civilian space programs. A series of flights started three years earlier, 1962. year ends Discover 37 and 38. Finding a suitable system for the hitherto unknown needs, new modes and equipment, saved the considerable amount of time, effort and financial resources.

By the end of the 1950s, when all the program objectives were achieved, it was a real success. But what will Discoverer carry to the universe? After all, it depends on the development of intelligence satellite systems Samos and Midas. It is obvious that in the planning of flights the most important role will be the photographic equipment.

There are three ways of getting photos from space. Sending the most visible television image from the satellite to the ground station, so that the transfer of the so-called. ťrealnom vremenuŤ, or the signal from the camera is stored on tape VTRs until a connection is made with the receiving antenna. It is considered to be the best mode. However, the image details Earth's surface observed the TV camera of the universe at that time does not show sufficient detail. Another possibility is to use photographic film exposed above the target and stored to later return the satellite to Earth. In this case, everything depended on the safe capture of the capsule, which is not expected in most attempts!

Finally, the third hybrid system has been selected, with a conventional satellite film camera and an electronic device for reading an exposed and developed movie that transmits radio-to-receiver images to receiving stations. The project has been proposed and developed Eastman-Kodak. It was the best of three ways, and at the same time the first practical satellite photo system. The process was so successful that NASA also chose to capture the Moon during 1966. and 1967. years. The system is based on Kodak'sBimatŤ process, and a typical example of equipment designed for satellites Samos tried out the Discoverer. Divided into the camera, a processor and a part of the reading, the system is expose film in front of a lens with a large and one with a small focal length. After exposure the film is coming to the part of the development. There is pulled by the drum and prevent Bimat or developer layer, made of gelatin soaked in the developer solution / fixed. Bimat process gives a positive image as the silver halides soon reduced to pure silver and undeveloped silver ions diffusing cross the network. After that, the two areas are separated, and the negative of dried small heater. Positive on the network is not used. Negative is then wound onto a reel in front of the reader image.

In CBS labs, a special scanning system with electronic air is transmitted over a phosphor-covered drum and thus creates a focal point that focuses on the lens lens system. The moving point exceeds 6,1 cm of wide negative in 17 thousands of crossings, 0,25 cm in length. After a horizontal transition, the film moves for the next reading for 0,25 cm. The procedure is repeated until the end of the image. The light passes through the film, changes the glow depending on the negative density and reaches the photomultiplier tube. It generates an electric signal proportional to the brightness of the light beam. This signal is finally amplified and emitted by the transmitter antenna to Earth. The whole device has a weight of barely 70 kg. The image obtained was worse than the original, but given the capability to rescue the capsule, and that means a lot, so Eastman's photographic system becomes the main load of the first Samos satellites.