The Н1-Л3 project was too large for one enterprise (in the USA Apollo had more than 20000 organizations). OKB-1 Korolev was appointed chief on Н1-Л3. The lunar ship itself was commissioned to develop the OKB-586 (Yuzhnoye Design Bureau in Dnepropetrovsk), and Yangel was appointed head of this unit.
In general, the H1-L3 project was completed on December 30 1964 of the year, at the same time the preliminary deadlines for the implementation of all stages were set. The first launch of the HNNUMX was to take place already in the 1 year, and the first cosmonaut on the Moon could have landed in the 1966-1967 year, which would make it possible to get ahead of the Americans who appointed the landing on the 68 year.
But as soon as the Yuzhny began the detailed development of the lunar ship, it turned out that previous estimates of the mass of the LC turned out to be greatly underestimated, and it was impossible to keep within the previously established mass. This happened because of a too rough approach to the LC in the draft approach. For example, the horizontal speed of the device during landing did not actually allow the radar altimeter, which was planned to be installed on the LC, to determine the actual height. The speed of the device, estimated at one of the flight segments in 30-40 m / s, would in fact be 200-300 m / s. In the first version, the LC weighed only 2.2 tons, and it was designed for two people. To eliminate these and other shortcomings, we had to increase the mass of the vehicle to 5.5 t, and reduce the crew to one person.
Initially, Yangel wanted to leave room for a second astronaut in the lunar cabin, but still it turned out to be impossible. Weight reduction was the main task facing designers, for each innovation that would reduce the weight of the lunar ship by one kg, a bonus in the amount of 60 rubles was awarded. Improving some systems of the orbital part, it was possible to reduce the mass only by 500 kg.
Determining the current speed and height after the separation of the D-block also proved problematic. The amount of fuel needed and all related parameters, such as the location and shape of the fuel tanks, depended on how efficiently this system worked.
The created radar system was called "Planet". She had four antennas. The first three created beams spaced apart from each other by 120 o, and by changing the signal frequency due to the Doppler effect, the ship’s horizontal speed could be accurately determined. The fourth antenna is directed perpendicular to the surface and served to determine the height. Such a system turned out to be relatively simple and reliable, and although it did not work for its intended purpose, Planet showed its reliability during the AMC E-8 flights (automatic delivery of lunar soil to Earth).
When conducting tests of the radar on board the MiG-17, some problems were found that were solved. Due to limitations, Mishin (who continued working for the deceased Korolev) only allows you to place 280 kg of backup fuel, which also delays the creation of an altimeter radar, which must now very accurately measure to avoid fuel overspending.
In 1967, Mr. Yangel notifies Mishin that the lunar ship will be ready no earlier than 1971 of the year (i.e., three years late). In 1968, the program again undergoes changes. Originally it was planned to land at the lunar equator, i.e. the lunar orbital ship would have been in equatorial orbit and would fly every hour over the landing site of the lunar cabin. This greatly facilitated the convergence and docking of vehicles, but at the same time, the most interesting places for landing are not always located exactly at the equator. In the case of choosing another place, the procedure of approaching the lunar compartment (after its launch from the moon) and the lunar orbital ship, which was able to get above the landing site 2-3 times, was more complicated. In this case, there were three options:
The lunar ship was equipped with an accurate inertial navigation system that allows you to perform complex maneuvers in circumlunar orbit for docking with the orbital ship.
After the launch from the surface, the lunar ship gradually changed its orbit until it was combined with the orbiter. In this case, no complicated navigation equipment was required.
The lunar ship calculated the trajectory of rapprochement before the start from the moon, and, starting from its surface, carried out the docking according to a calculated scheme.
The Americans chose the first option, in the Soviet program they preferred the second one. The docking was to take place at an altitude of 25-30 km. Since the digital computer could not be used for these purposes (because of its absence), an analog system was developed that calculates the necessary elements of the orbit and the moments of switching on the propulsion system. Such a system for the lunar ship was created and was very effective.
In contrast to these tasks, the task of maintaining the center of mass was very difficult. The center of mass should not have moved more than 3 cm (!). This required a special arrangement of the fuel tanks of the E-block and engines of precise orientation. The astronaut in the lunar cabin was also severely constrained in his actions. All equipment LK also had to develop and place in accordance with these requirements. To compensate for the displacement during landing and take-off, when there was a decrease in the mass of the lunar module in the process of fuel consumption during engine operation, such heavy elements of the apparatus, like batteries, constantly moved.
That part of the apparatus, which directly touched the surface, was called the abbreviation LPU (lunar landing device). In addition to ensuring the landing, this module served as a launching pad for block E, with the help of which the lunar ship took off from the moon. The hospital also housed equipment that was activated only during the descent, or it could work in lunar conditions and was used before take-off from the surface. It was a radar altimeter, parabolic antennas, chemical current sources, three tanks (a fourth was later added) with water for an evaporative cooling system and a video camera that would shoot an astronaut on the surface. The hospital had a mass of 1440 kg with the full weight of the lunar spacecraft 5560 kg. As mentioned above, due to the mass limitation of the vehicle, the propulsion system could move the ship no further than 100 meters from the pre-selected point. Quite large craters could be in this place, so the lunar landing gear had to ensure a normal landing (and subsequent take-off) to the surface so that the device could function normally even when it formed rather large angles with the surface (up to 30 degrees) . It was also necessary to ensure the "blind" landing of the device in unmanned versions, when the absent cosmonaut could not control the operation of automation. Before the designers there is a question: what exactly should the apparatus touch the moon? The minimum option was the use of three landing pillars, such a scheme was used for landing on the moon of their "Surveyors" (automatic devices for research and photographing the surface). This option was not suitable for the Soviet lunar ship, since it did not provide the necessary stability and did not guarantee the preservation of the center of mass. Health facilities begin to develop several design offices at once, and a large number of different projects appear: from several supports to a special landing ring. In the end, there were two possible schemes: passive and active. In the first case, the device would land on several passive supports, but then it was necessary to ensure a very smooth approach to the surface. In the second case, the landing supports had their own corrective engines, which were switched on directly at the moment of contact for precise positioning of the vehicle.
For the final choice, a whole complex was created to simulate landing on the lunar soil: a large room was filled with volcanic tuff from Armenia (in its physical properties it resembles lunar regolith), and an imitation of the touch of the Moon was carried out in it. Tests have shown that an active circuit is preferable (solid-fuel engines were used), which was chosen for the lunar ship.
The lunar cabin was designed to accommodate one astronaut. In the center (relative to the astronaut sitting in the cockpit) there was a large window in which observations were made during the landing. Above it was another window that was to be used to observe the docking process with the lunar orbital ship. The most important controls of the device were to the right, and less so to the left of the person sitting inside.
An additional requirement for the developers was that the LC should have been capable of an unmanned flight: it automatically lands on the moon and automatically docked with the orbital ship. This was required both for testing the apparatus in an unmanned mode and for carrying out possible "rescue" operations, when, in the event of a damage to the E block, the LC could not take off from the moon and the astronaut remained on the surface. This required, of course, the simultaneous launching of two vehicles to the Moon: a worker (manned) and a backup. The autonomy of the lunar ship was provided by television cameras, which made it possible to see everything happening on Earth and remotely control the spacecraft.
In the back of the lunar cabin housed a disc-shaped module with equipment such as:
Power management system
Equipment for docking.
Initially, in the lunar cabin was supposed to use pure oxygen under pressure 0.4 atmosphere. But it was too flammable environment, therefore, subsequently the share of oxygen, adding nitrogen and increasing the pressure to 0.74 atmospheres. At the same time, although it was required to increase the mass of air reserves by half, however, the ship became safer in terms of fire hazard. At the last stage of the landing of the lunar cabin, as already mentioned, the astronaut took over the management. However, at the time of development of the landing gear, the creation of such a system was hampered by a complete lack of experience. Everything had to start over. In addition to maintaining the center of mass, it was necessary to ensure full performance even in the event of possible depressurization of the cabin. Although all systems had to remain intact during the depressurization, the spacesuit was designed only for 10 hours, i.e. in this case, it was necessary to immediately return to the lunar orbital ship. In this regard, had to abandon the use of foot pedals. Developers had to study the experience of aircraft designers, who created in those years vertical take-off and landing aircraft.
The placement options for dashboards and portholes were also worked out for a long time. It was found that for viewing the surface of the moon during landing, the optimal viewing angle is 7 degrees. The porthole, used to control the descent, had a coordinate grid for determining and correcting the place of contact with the ground. I also had to create a spacesuit that allowed me to work directly on the moon for quite some time. It had the name "Krechet" and became the prototype of the "Orlan" spacesuits, which are used today by Russian astronauts to work in outer space. "Merlin", as well as its present analog "Orlan" is a very complex device. He did not put on a man, but on the contrary, a man went into a spacesuit - for this there was a hatch in the back of this equipment. It had a system of special stretch marks and clamps, which were necessary to ensure human immobility during maneuvers, since with a small mass of the entire lunar ship, the displacement of the center of gravity of the entire apparatus due to the awkward movement of a person could lead to very big troubles.
To test the spacesuit (as, indeed, and not only him), a full-scale mockup of the lunar ship was built, on which various tests and trainings of the crew were conducted. Probably many have seen these shots in the chronicle. In order to mimic lunar gravity, which is 6 times earthly, a special inclined tower was built. The man walked along its outer wall, which formed an angle of approximately 30 degrees with the vertical. At the same time, the gravitational pull pulled down and took most of the weight (so as not to fall, the person in the Krechet was hung up on a cable before these operations), and only one-sixth of the weight remained on the support, which provided "lunar conditions". Since the spacesuit turned out to be quite large, it was necessary to re-develop the hatch. For the same reason, the placement of instruments and units of the lunar cabin was also consistent with the location of the person (again, to preserve the center of mass).
In order to save mass, the docking station had a fairly simple device (compared to the same node, in Soyuz, flying in near-earth orbit today). This simultaneously reduced the cost of the device and increased reliability. Since the astronaut moved from the lunar orbiter to the landing module and back during the spacewalk, there was no need for any rigid docking to ensure a tight transitional tunnel between the modules. Developed for these purposes, the system "Contact" provided a simple approach of the vehicles (after the launch of the lunar ship from the moon) and their mechanical capture.
This system should have been developed and tested by 1968 year. It was planned to launch two "Soyuz" in unmanned mode to work out the docking, after which a similar flight of the manned "Unions" was to be carried out. However, unmanned attempts failed, and the launch immediately after that of the Soyuz-1 with Komarov also ended in tragedy: he was killed when landing on Earth. Instead of four "Soyuz", more than a dozen vehicles were spent, and the Soviet lunar program was delayed (although not only because of this) by a year and a half. Contact was fully operational only during the Salyut program (manned orbital stations), more precisely, by October 1971. Together with the orientation-stabilization system and fuel for it, the lunar cabin weighed about 1300 kg.
In total, the following systems were present in the lunar ship of the Soviet program H1-L3.
Automatic control system. This system, the fundamentals of which were taken from guidance systems from military missile complexes. It provided control of the ship at all stages of the flight of the lunar module: descent, landing, takeoff and docking. All the calculations necessary for the operation were provided by the onboard computer (on-board electronic computer), which processed the data coming from the measuring sensors and gave instructions to the propulsion system. Basic orientation data provided gyros and radar, measuring the horizontal and vertical velocities of the device. The astronaut had the opportunity to adjust the commands issued by the on-board computer, and he also saw near the surface the point where the device sat down (using special symbols on the window) and could change it (choose a new landing site located not further 100 meters from the old place ). All calculations were performed in three independent parallel streams to reduce the number of possible errors.
Radar system for measuring the speed of the device. Located outside the spacecraft near the equipment for access to the lunar surface.
Lunar landing device.
Docking system "Contact". She was lightweight and provided simple physical contact and capture of ships. "Contact" could work both manually and automatically.
Power distribution system. It is located in the lower instrument compartment. It consisted of a system of electrical cables and five chemical batteries: three in the hospitals and two in the lunar cabin. These electric batteries had a relatively long shelf life: they could be used for their intended purpose even after three months in space.
Analyzer remaining onboard systems that determine their health.
Cabin for an astronaut.
On-board computer. Used in the automatic control system. Speed - 20 000 operations per second. Provided parallel computations of three independent data streams.
Antenna opening system.
Antennas themselves: two meter parabolic antennas for high-speed data transmission and broadcast of television images and one omni-directional antenna for communication at low speed with the Earth and the lunar orbital ship.
TV cameras. Designed to transfer frames of the lunar surface during the landing of an unmanned vehicle and transfer the video image of the astronaut, going to the lunar surface and working on it.
A system that transmits telemetric data on the operation of all ship systems.
The suit "Krechet". Provided access to open space and to the surface. Autonomy - 10 hours.
The system maintains the atmosphere of the lunar cabin.
Thermal control system that provides normal temperature at a temperature outside the lunar apparatus from + 130 ° C to -200 ° C.
Scientific equipment. Because of the limitations of the mass of the LC, it was not finally chosen, however, it is clear that the main "scientific experiment" before 1969 was the installation of the Soviet flag on the Moon before the Americans set their own.
Fire extinguishing system.
The propulsion system, which was designated by block E and was intended for a soft landing and take-off from the moon, was given very close attention. Already at the first sketches of the lunar ship there were drawings of this block. It was originally planned to meet the 510 kg, but it soon became clear that this was unrealistic.
For reliability, the E unit had not one, but two engines: the RD-858 and the RD-859. As soon as block D was separated from the apparatus, they were launched simultaneously. If automatics noticed any failures in the first engine, it immediately turned off, and the landing gear returned to the second, spare engine to the lunar orbital ship. If everything was normal, the lunar module continued to decline on the main engine, while the second remained in reserve at that time. It is clear that would cause the failure of two engines at once.
In descent mode, it was necessary to develop 850 kg thrust, and in takeoff mode - 2000 kg. RD-858 could change its power within these limits, and RD-859 had a fixed value - 2000 kg, i.e. landing with him was impossible. Throughout the operation of Unit E, 2900 kg of fuel was supposed to burn out.
Creating a reusable motor with adjustable pitch required titanic efforts. For its development it was necessary to invent new materials and technologies. A key problem in the development of block E (as well as the lunar landing gear) was the "reflection" of gases flowing from the nozzles from the lunar soil during landing. In the American Apollo, various engines were used for landing and take-off, which made the task much easier. A similar option in the Soviet project was not possible due to limitations on the mass of the entire apparatus. If the American lunar module had a soft landing engine that was contaminated or damaged when in contact with the surface (which happened several times), then it did not matter. For the lunar ship had to develop a system that sent a jet of gas in the vicinity of the surface as far as possible from hospitals. When the E block was turned off (in the “landing” mode), the nozzles were immediately closed to prevent foreign particles from entering them, for example, lunar dust, which was rising at the moment of touching the ground.
To maintain the center of mass of the fuel tanks (volume on 1.2 м3) had to be given an unusual form: the oxidizer was consumed 2 times faster than the fuel. Long-stored self-igniting components: hydrazine and nitrogen tetraxide were used as a fuel / oxidizer. The mass of the fully charged unit E was 2950 kg, the empty stage weighed about 550 kg. For a soft landing, it was necessary to burn about 700 kg of fuel, and takeoff required 2100 kg.
For corrective maneuvers was designed a separate propulsion system. As in block E, it used hydrazine / nitrogen tetraxide. It was located above the lunar cabin and could provide not only horizontal, but also vertical corrections. For enhanced reliability, the lunar ship had not one, but two independent orientation systems, and could work even in the case when one of them completely failed. For their operation, there was 100 kg of rocket fuel components. As in the case of the main fuel tanks, it was necessary to tinker with the center of mass: the tank with the oxidizer was located inside the fuel tank and had a special structure.
To supply fuel to fuel tanks, helium was being pumped up under the pressure of 10 atmospheres, which pushed the liquid out of the tank. The engine could be turned on repeatedly, the duration of the minimum pulse was 9 milliseconds, the maximum - 10 seconds. For nozzles placed at an angle of 20 degrees to the horizontal, a new graphite-niobium alloy was used.
On top of the entire ship, in addition to the orientation system, there were radiators of the thermal control system and the seizure of the docking station.