Part 1 - Part 3
In the previous part of The Guide, I promised to leave for dessert the most delicious part of exposing the "lunar deception" - the claims to the Saturn-Apollo rocket-space system. The arguments here, it seems to me, are very simple and obvious: yes, photographs and film materials could well have been taken on Earth (which is almost admitted), but this could well be explained by a laboratory defect in film development, poor quality of the images themselves, etc. I want to make one important digression. Indeed, in the so-called documentary and reporters it is often customary to use "staged shots" and "reconstruction". Let's not be hard on creative workers, because in real life, where current events take place, there is often no good studio light, movie cameras fail, expensive lenses break, spotlights burn out … In addition,you can simply not have time to capture the historical shot of the century!
Nowadays, it has become common knowledge that the film crew on November 7, 1941 did not manage to film Comrade Stalin's speech on Red Square, and almost by the decision of the Politburo he was obliged to deliver the speech a second time. The substitution was easily revealed, for Stalin performed in a severe frost, during a blizzard, while on the film, when he opened his mouth, he did not even have steam! On the other hand, his speech was broadcast live on the radio, and Stalin himself was seen by thousands of participants in the 1941 parade.
Mockups of two missiles: H1 (left) and Saturn-5 (right)
Also recently, the British admitted that many speeches and speeches of Prime Minister Winston Churchill during the war years were portrayed for photo chronicles by his double, and even on the radio (!) The text on behalf of Churchill was recited by an artist with a similar voice. However, this does not deny the very existence of Mr. Churchill as such.
Let me give you a very harsh and dangerous comparison. When Yuri Gagarin was launched, no reportage, and even more so protocol, shooting was not carried out. Only technical fixation and only for special storage. Given the political significance of the event, the need to replicate high-quality propaganda material, it was decided in a few days to make a "reconstruction" of the farewell before the launch with the real Gagarin and a real missile of the same class. As usual in such cases, they filmed from many cameras, made a solemn report at a fueled (!) Rocket, hugged, kissed, let out a tear …
From the point of view of the laws of cinema, this is all correct and competent. Does this cast a shadow on Yuri Gagarin? Not at all, because radio amateurs all over the globe received its signals, the ship itself was clearly visible at many observation posts, and most importantly, such "balls" with antennas of the "Vostok" type were launched into darkness both before April 12, 1961, and after, only they were called differently, and instead of an astronaut there was a powerful camera with a good supply of film on board. Such photo reconnaissance planes were launched at least once a week, so the reality of the implementation of Yuri Gagarin's flight raises no questions.
Promotional video:
As for the Saturn rocket and space system, all the missiles of this family were hastily disposed of in the mid-70s, the documentation and working units were destroyed, only a few museum models remained, which could well have been originally dimensional and weight dummies for various static tests, the presence of which does not prove anything. For example, in the USSR, more than ten full-size 11A52 or "H1" products were produced - this was the name of the Soviet lunar rocket of the manned flight program to our natural satellite. At the same time, only four products numbered 3L, 5L, 6L and 7L were actually launched from the Baikonur test site, one - 4L was put aside in the “reserve” warehouse, the rest were used for various tests, training of the launch team, etc. Several ready-made missiles of number 8L,9L and two more unassembled sets were simply scrapped after the program was closed …
At the same time, we all understand that even if the N1 rocket were exhibited at VDNKh, this would not prove anything, because its sad story is well known.
RD-270 engine
The Energomash Museum has the largest Soviet single-chamber liquid-propellant rocket engine (LRE) of the RD-270 type with a thrust of about 640 tons at the ground. But this is just a technological mock-up - a semi-finished product for one of countless tests. In reality, this engine (unfortunately) was never brought to the stage of flight tests. "Alive" and "healthy" are still prototypes of the lunar spacecraft LOK (11F93) and the landing cockpit LK (11F94), on the Internet anyone can easily find their photos.
LC has become a teaching aid
LK has become a teaching aid Americans are proud to show their museum Saturn-5 rockets, allegedly providing the delivery of astronauts to their destination, and, in addition, super-powerful LRE of the F-1 type with a thrust of about 680 tons at the ground, without which to raise a rocket into the sky weighing about three thousand tons (!) is simply not realistic.
Well, well, we can in return show our museum engines, models of lunar ships and cabins, and what - we also flew to the moon ?! Although, of course, also an option. Therefore, returning to the topic of our story (and all the previous ones were just a necessary digression), I want to state directly and bluntly: you cannot intimidate us with museum exhibits! These are all fake props and nothing more. Our main task is to analyze all the available statistical, film and photographic materials of real launches of Saturn missiles in order to answer one extremely important question: whether the Saturn-5 rocket and the Apollo spacecraft meet the minimum technical characteristics required to deliver two or three man to the moon and their safe return to their native Earth?
LRE F-1. Also a big piece of iron!
All subsequent arguments will relate to two categories of research methods: the analysis of numerical statistical data, and the study of the behavior of a rocket and a ship directly during flight.
Fake "legend"
One of the most stupid myths and misconceptions about the Saturn-Apollo program is that its impeccable (from the point of view of the official press) implementation is based on a deep study and thorough testing of all components of the lunar program. Alas, this is not entirely true, or rather, not at all. A careful study of the preparatory period from 1964 to 1969 before the start of manned lunar missions is full of very juicy details.
The first test flight of the Apollo spacecraft on the Saturn-1B auxiliary light rocket took place on February 26, 1966. Having risen to a height of 488 km, this object flopped down a ballistic trajectory into the Atlantic. The purpose of this mission, according to NASA, was to test a prototype Apollo spacecraft and check its descent vehicle for a controlled entry into the atmosphere. However, during the descent, the ship lost roll control, entered the uncontrolled spin mode and fell into the ocean with exorbitant overloads. The purpose of the second flight on July 5, 1966. was the study of "the behavior of liquid hydrogen in zero gravity." Here is how the yearbook of the Great Soviet Encyclopedia (TSB) for 1967 describes the results of the flight: “The last stage (S-IVB rocket) of the experimental Saturn IB SA-203 launch vehicle was launched into orbit with incompletely consumed fuel. The main tasks of the launch are to study the behavior of liquid hydrogen in a state of zero gravity and to test the system that ensures the re-engagement of the main stage engine. After carrying out the planned experiments in the system for removing hydrogen vapor from the tank, the valves were closed, and as a result of the pressure increase, the stage EXPLODED on the seventh loop. The third flight this year on August 25, 1966 was again suborbital, but the range was impressive - the object was caught already in the Pacific Ocean. The third flight this year on August 25, 1966 was again suborbital, but the range was impressive - the object was caught already in the Pacific Ocean. The third flight this year on August 25, 1966 was again suborbital, but the range was impressive - the object was caught already in the Pacific Ocean.
One of the sources dryly states that the separation went well, despite the "minor" problems with valves in the engine cooling system. And even with very insignificant fluctuations of the upper stage, which was hardly brought back under control (!?) That is why it, apparently, ended up in the Pacific Ocean instead of orbit. The descent of the capsule in the atmosphere was "steeper than expected" (!?), The search for the fallen capsule was carried out for about nine hours! Here we can only add for completeness of impressions - during bench tests of the second stage of the Saturn-5 rocket for a 350-second interval of operation on May 25, 1966, a flame flared up in two places, and the test had to be interrupted. Three days later, when removing the same stage from the stand, its hydrogen tank suddenly exploded, and five workers were injured. The booth was seriously damaged. Then,On January 20, 1967, during ground tests, the S-IVB-503 stage exploded, which was being prepared as the third stage for the Saturn-5 rocket, serial number 503 for the legendary Apollo-8 flight. Well, to top it off, what everyone knows: on January 27, 1967, three astronauts in the Apollo 1 spacecraft were burned down during ground training just a few weeks before their launch! After that, the commission to investigate the incidents came to the conclusion: manned flights on this kind of equipment were covered with a copper basin for the next indefinite time. On January 27, 1967, three astronauts in the Apollo 1 spacecraft burned down during ground training just a few weeks before their launch! After that, the commission to investigate the incidents came to the conclusion: manned flights on this kind of equipment were covered with a copper basin for the next indefinite time. On January 27, 1967, three astronauts in the Apollo 1 spacecraft burned to death during ground training just a few weeks before their launch! After that, the commission to investigate the incidents came to the conclusion: manned flights on this kind of equipment were covered with a copper basin for the next indefinite time.
Further, there were two unmanned launches of the Saturn-5 rocket - one in November 1967 under the Apollo-4 designation, when the ship with all the power of the rocket was able to launch only into an elliptical orbit with an apogee of only 18 thousand kilometers, and the second under the Apollo designation -6 , when the rocket almost collapsed in the air, the engines of the second stage failed in flight, then there was a problem with the third, technical filming showed the partial destruction of some structural elements of the rocket, as a result, instead of simulating a flyby of the Moon along a highly elliptical trajectory with an apogee of up to 500 thousand kilometers, flew near the Earth and landed with a large error on an uncontrollable ballistic trajectory. And this is all that was done before December 1968 in terms of flight tests of the Saturn-5 lunar rocket before the first (!) Apollo-8 manned flight to the Moon. ApparentlyThe Americans decided not to carry out more test flights, not to spend money and nerves on them, but to send people immediately and immediately to the Moon, because our people - the main thing, people - will not let you down! And if they let you down, you don't feel sorry for them …
How much does Skylab weigh?
The biggest eyesore on the American lunar program is rightfully considered the very first Stars and Stripes Skylab space station, created by re-equipping the third stage of the Saturn-5 rocket. Officially, it is the largest single-piece space station ever launched on a long-term basis. This epoch-making event, which took place on May 14, 1973, also marked the end of the space career of the Saturn-5 rockets, for this was the last, thirteenth (!) Launch of products of this type.
Usually, when a payload is prepared ahead of time for a specific carrier, its weight and size parameters are selected based on the maximum capabilities of the carrier. For example, the Vostok ship weighed a little less than five tons because the Vostok rocket, which is also an 8K72K product, could not do more. Exactly for the same reason, the Soyuz spacecraft has been weighing a little less than seven tons for the last forty years, and the Salyut-type stations - about 19 tons. I would like more, but the old "Proton" no longer pulled. Accordingly, when the Americans decided to surprise the world and build a grandiose space station, we had the right to expect that "Saturn-5" will go to the record of carrying capacity. In all flights of the Apollo spacecraft, from A-4 to A-17, the weight of the payload only increased, and in the A-15 flight a record was set - 140 tons of cargo in low-earth orbit.
In the Guinness Book of Records, there is the following official entry: "The heaviest object launched into near-earth orbit was the 3rd stage of the American Saturn 5 rocket with the Apollo 15 spacecraft, which weighed 140,512 kg before entering the intermediate selenocentric orbit." disappointing to learn that in the last record flight, according to official figures, the payload was only 74.7 tonnes. On the other hand, the calculations shown by me in the third part of "Pepelatsev" prove that "Saturn-5" could well have put a payload weighing up to one hundred tons into a reference target orbit of the "Skylab" type (altitude 435 km, inclination 50 degrees)! Not to mention that to a very low orbit (the so-called LEO) - not less than 120 tons. A reasonable question arises: where is everything else?
We were waiting for a demonstration of power, and we were shown a carrier, which, instead of a hundred tons, barely finished seventy with a penny … The detailed description is as follows: “Skylab 1 Nation: USA. Program: Skylab. Payload: Skylab Orbital Workshop. Mass: 74,783 kg. Class: Manned. Type: Space station. Spacecraft: Skylab, Apollo ATM. Agency: NASA MSF. Perigee: 427 km. Apogee: 439 km. Inclination: 50.0 deg. Period: 93.2 min. COSPAR: 1973-027A. USAF Sat Cat: 6633. Decay Date: 11 July 1979 . Photo on the left: Skylab with one “wing”. The left wing was lost …
However, analyzing the American records, I discovered an amazing thing: a shortage of payload and work in three quarters of the force combined with a record load ever raised into low-earth orbit - on this May day in 1973 (this is how it comes out) the Saturn-5 rocket, tearing her navel, she pulled as much as 147 tons into space on her hump! True, this absolute world record (for some reason) is nowhere and is not recognized by anyone. However, the most interesting part began. And what exactly is included in these 147m?
First, the second stage of the rocket entered orbit (dry weight about 42 tons) and another 13 tons of fuel residues, which is three times higher than the usual remnants for this stage (usually no more than 4..5 tons). Secondly, the Skylab itself weighing about 75 tons. In addition, NASA was dragging frank trash into orbit: a fairing weighing almost 12 tons was launched into orbit !!! This fact is extremely unhealthy. Experts will understand me: why drag the fairing to a height of 450 km? Typically, this structural element falls at altitudes of 90-130 km long before the MSZ orbits. It just makes no sense further. For example, seven Salyut, one Mir, several modules such as Kvant, Spektr, Kristall, and others, and several segments of the ISS were launched into orbit by the Proton rocket. At the same time, the Soviet rocket always drops this same fairing in flight long before entering orbit. And all other existing carriers drop the fairing at the launch stage - this is energetically more favorable.
For thousands of space launches, only a few cases of violation of this unwritten rule can be recalled. In addition, the first stage adapter weighing 5 tons has not yet separated. And he, too, was taken with them into orbit. Apparently this was planned, otherwise the balance will not converge. In fact, apart from the 75-ton station, the largest batch of garbage and scrap metal, weighing 25 tons, not counting the weight of the last stage, was launched into space! You can, of course, put the question differently: they were not chasing the maximum weight, 75 tons was enough for them. This is a good argument, only it has one small drawback: the Skylab station came out "unfinished", it doesn't even have its own engines! Although the resources made it possible to easily attach any of the ready-made propulsion units, for example, those stored from the Apollo LM landing modules.
It turns out that, having the opportunity to launch a 100-ton fully-functional station, the Americans decided to voluntarily limit themselves to 75% of the capacity, and the rest was "thrown" from above with junk, as Soviet schoolchildren did before, handing over waste paper … As a result, Skylab flew after 1973 without the slightest opportunity orbit correction, and in 1979 fell completely uncontrollably in the wilds of Australia. To save this "miracle", which has been actively working for only six months, no one began or did not want to … If we start picking the remaining 75 "legal" tons of "Skylab", then everything is extremely vague and mysterious here (it should have weigh 77 tons, but the solar battery was dropped in flight, leaving 74.7 tons of official weight).
The station consists of the following elements:
Weight distribution of Skylab station structural elements
(according to the book "Skylab Orbital Station" by L. Bellew E. Stullinger, translated from English M. Mechanical Engineering, 1977)
| Element | Length, m | Diameter, m | volume, m3 | Weight *, t |
| Berthing structure | 5.2 | 3.0 | thirty | 6,3 |
| Astrokomplekt ATM | 4.5 | 3.4 | 5.0 | five |
| Airlock | 5.2 | 3.2 | 17 | 22.2 |
| Equipment compartment | 0.9 | 6.6 | 2.0 | five |
| Orbital block | 14.6 | 6.6 | 275 | 35.4 |
So, all this junk in total pulls 71t in total. And according to official figures, it should be about 77 tons. Already a discrepancy. There is a version about a discrepancy: according to NASA data, the mass of the ATM astrocomplete is indicated twice as much as in the book of Bellew and Stulinger ≈11.8 tons instead of 5.05 tons. (Or out of the blue ~ 6.7 tons were credited) Or take a miraculous airlock weighing 22 tons - this is more than the Soviet Salyut station! Look - the average density of the chamber space is 22 / 17≈1.3 t / m3. But there is neither fuel nor anything heavy inside. It seems that the compartment is filled not even with water, but with sand … But the Soviet Salyut station was three times longer - 15m; and wider in diameter - 4.15m. What did they make this camera out of - lead !? But the average compartment density of spacecraft is in the range of 0.25..0.35 t / m3. Even the average density of the descent vehicles is less than 1 t / m3 (otherwise they would have sunk in the water), although the descent vehicle is the densest, heaviest and most durable element among spacecraft.
Thus, the airlock of the Skylab station with a volume of 17m3 should weigh four times less than ~ 5..6 tons. (This means that they added ~ 16t). We can talk separately about the "armored" head fairing weighing ~ 12t. And this despite the fact that he does not even protect the entire station, but only part of the crown! For example, the standard fairing of a Delta-2 rocket (diameter = 2.9m; height = 8.48m) weighs only 839 kg. But the fairing of the Atlas-2 rocket (diameter = 4.2m; height = 12.2m) weighs as much as ~ 2 tons. The heaviest American fairing of the Titan-4 rocket with a diameter of 5.1 m and a height of 26.6 m (five diameters in length!) Weighs only ~ 6.1 tons. So, the sum of the additions of the weights of the parts of the Skylab station and the payload has already totaled about 30 tons. Here we add things that exist only in virtual reality,and the existence of which is impossible to verify - these are the superplanned remnants of 8 tons of fuel and a semi-mythical adapter of the first stage (~ 5 tons), which was allegedly pulled into space. This means only 30 + 8 + 5 = 43t. Remains net 100-43 ≈ 57t.
Summary: The payload capabilities of Saturn-5 in the Skylab-type target orbit did not exceed ~ 60t. This is an extremely important conclusion for us, because in order to carry out manned flights to the Moon using a single-launch scheme, it is necessary to have a rocket that could send at least 45-50 tons of cargo to the Moon, which is equivalent to a payload capacity of at least ~ 130 tons in a low Earth orbit. … Accordingly, if you do not have a carrier for 130 tons, but there is half as much strength, then you can send to the Moon at best twenty-five tons of commercials, which is enough for a flyby mission, but not enough for landing on our natural satellite.
Since the incident of "Skylab" is widely known, this thorn in the American eye will exist for a long time and drink their bourgeois blood, and what is a shame - everything has already been recorded in the past, nothing can be changed …
Kerosene or hydrogen?
This curious argument is widely accepted on the Internet thanks to your humble servant, who, for fun, decided to pose the opposite problem: well, let Skylab weigh 60 tons or even all 75 tons. What are the characteristics of the rocket in terms of the specific impulse of the second stage, so that the payload is equal to the weight of the station, so that excess ballast is not required? I want to note right away that by fixing the stage masses, and varying only the specific impulse of the second stage, I am acting incorrectly, because this problem may have another solution - without changing the specific impulses of the engines, simply reduce the absolute masses of the stages themselves. Nevertheless, having fixed the mass and specific impulse of the first stage Isp ~ 304 sec. (it is already too low and can hardly be much lower), I came to an interesting conclusion,that to launch a load of seventy-five tons, the second-stage engines must have a specific impulse Isp ~ 380 sec, i.e. much lower than the range of "hydrogen" rocket engines (they simply do not have Isp below 400 seconds).
And the flame is clearly not hydrogen …
Further, taking into account the "lightweight" version of "Skylab" no more than sixty tons, it turns out that with a fixed canonical first stage of "Saturn", the second can be made "kerosene", because the required specific impulse of the engines will drop to values of the order of Isp ~ 330 sec. … can be easily implemented using oxygen-kerosene rocket engines with good high-altitude nozzle nozzles. Moreover, a funny photo of bench tests of the second stage Saturn-5 engine under the J-2 designation, which has a red-yellow hydrocarbon glow instead of a pure blue torch, was discovered.
In addition, there is a mass of evidence in favor of the fact that the Americans did not manage to realize and complete the "hydrogen" with a thrust of almost a hundred tons: during 1965-1967 there were repeated accidents (both in flight and at the stand) of hydrogen stages with J-2 engines, which ended in explosions and complete destruction of the structure. However, instead of (or together) with the above thesis about replacing unreliable J-2 engines with something else (with worse characteristics), another argument remains: for the implementation of a rocket and space system of such a high weight (about 3000 tons) with only five engines in the first stage, this traction five must be particularly outstanding!
The F-1 engine: reality and fiction
Many researchers just point out, first of all, not to the problems with fine-tuning the "hydrogen gas" at the upper stages, but to the impossibility at that technical level and on those circuit solutions to implement a single-chamber rocket engine on kerosene and oxygen with a thrust of over 700 tons. There are many reasons for this, and the main one is the so-called. high-frequency combustion instabilities caused by the (roughly) lumps of unburned fuel mixture (like "detonating gas") appearing in a huge chamber, which burn out not evenly, but like microexplosions. As long as the engine chamber is small, this is tolerable. But with huge linear dimensions, detonation occurs in the engine, which enters into resonance, which destroys the engine housing. For many years, it was considered very problematic to create a single rocket engine with a thrust of over one hundred tons.
Soviet designers represented by V. P. Glushko and others came to an unambiguous conclusion: it is possible to make large rocket engines only in a closed circuit, when one (or both) components enter the chamber not in liquid form (liquid-liquid scheme), but as a hot gas (liquid-gas scheme), which sharply reduces the ignition time of fuel portions, and significantly localizes the problem of frequency combustion instabilities to reasonable limits. Nevertheless, the Americans insist that they have succeeded in doing something that cannot be in nature, i.e. a single-chamber rocket engine running on kerosene and oxygen in an open circuit with a liquid-phase supply of both components and a thrust of over 700 tons.
F-1 engine at the stand
The available photos of bench tests of this miracle engine also raise a lot of questions, because thick opaque smoke is pouring out of the nozzle there, behind the veil of which a flame breaks through only after a few meters! Even the employees of the test site, who had seen a lot of things, were surprised at the work of this "coke oven battery". A photo. F-1 engine on the bench Seeing this "black flame", the first reaction of the testers was to turn everything off immediately, until it exploded. But colleagues with a German accent explained that everything is fine, that it is "so necessary" …
One digression is necessary here. Unlike most Soviet rocket engines, which were made of two bonded solid casings (outer and inner), between which liquid cooling by one of the components (usually fuel, less often an oxidizer) flowed through ribbed channels, most American rocket engines of those years were a set of huge the number of thin tubes, which were fastened together by soldering and power bands, forming the usual shape of the chamber and the nozzle of the liquid-propellant engine. The tubes usually ran along the axis of the engine, and if you use a double set of tubes, then some kerosene flowed from top to bottom - from the head to the nozzle edge, and on the other (parallel), vice versa - from bottom to top, supplying heated fuel to the nozzle head.
I will not now discuss the advantages and disadvantages of each scheme, I will only say that our "sheet" casings were made of a cunning bronze alloy, and American pipes were made of nickel or steel. The difference is that the Soviet chrome bronze (invented not without a tip from the captured Germans) had better heat-conducting properties than steel and nickel. So, the researcher of the lunar forgery S. Pokrovsky in the article "Why the flights to the moon did not take place" points to the structural defects of the alloy from which these very tubes of the F-1 engine were made - this is the nickel alloy Inconel X-750. Without going into a detailed description of Pokrovsky's arguments, I will point out that, in his opinion, at that time, heat-resistant nickel alloys were still poorly studied, and as it turned out,this most experimental Inconel X-750 alloy in reality could not provide the necessary strength properties with the declared operating parameters of the engine.
According to Pokrovsky, the Americans quietly abandoned the rare nickel alloy, switching to more reliable heat-resistant steel. In addition, according to Pokrovsky's hypothesis, in order to ensure the safe operation of the engine on thin steel tubes, the Americans were forced to significantly reduce the temperature in the combustion chamber (by 15%), and as a result, to lose about 22% of the engine thrust. I must admit that I do not completely agree with the substantiation of the numerical estimates of this version, in particular, with the estimate of the contribution of radiant heat exchange of water vapor in the chamber of the F-1 engine, but I would like to note that there is undoubtedly a common grain in these hypotheses. Only I would justify it much easier and a little from the other end.
Leaving for some time the issues of combustion instabilities and the problem of detonation of fuel bunches in a large combustion chamber, I would like to talk about the heat-conducting properties of combustion chambers and nozzle parts of a liquid-propellant engine using qualitative examples. It was not for nothing that I mentioned that the Soviet chambers of such classic liquid-propellant rocket engines as RD-107 and RD-108 were made of special chromium bronze (and all copper alloys have excellent thermal conductivity), so even a very thick wall reliably transferred heat to flowing kerosene. Nickel and steel have a much lower thermal conductivity, so, all other things being equal, they are designed for a lower heat flux per unit surface area. The combustion chamber wall operates under unthinkable thermal loads: on the one hand, hot gas with a temperature of 3500K, on the other, kerosene flows with a temperature ten times less. If heat in the form of convective (contact) transfer and in the form of a radiant flow, which falls on each square centimeter of the chamber wall, is not removed and "transferred" to the flowing coolant (kerosene), then the wall temperature will begin to rise (up to the gas temperature), and the metal will melt easily.
In turn, the magnitude of the heat flow is determined by both the gas temperature and its pressure (gas density). Obviously, the combustion temperature is determined by the chemistry of the process, and in fact, for most kerosene liquid-propellant engines, it differs by no more than 5-7%. Pressure is another matter - the gas can be hot, but its density will be low, and the heat flux will be small. In all the first Soviet kerosene rocket engines without serious curtain cooling by liquid injection into the wall zone (except for the engine head zone), the pressure in the chamber varied from 52 to 60 atmospheres. All the first American kerosene rocket engines, created by different companies (!), Such as the LR87-3 of the Aerojet company with a thrust of 73 tons for the Titan-1 rocket had an operating pressure of only 40 atm, and its twin brother LR79-7 with a thrust of 75 tons,created by the bitterest competitors from "Rocketdyne" for missiles of the "Delta" type, had an operating pressure of as much as 41 atm!
Another well-known series of LR89 engines of the same Rocketdyne for the Atlas-type missile family was content with only 42 atmospheres in the chamber, which by the beginning of the 90s had been brought to a level of only 48 atmospheres. The reader, of course, may doubt the existence of a connection between the tubular design of the chambers of American liquid-propellant rocket engines and their operating parameters. But here's the paradox - the same LR87-5 without altering the chamber and nozzle, after replacing the components from kerosene and oxygen with aerosin-50 and nitrogen tetroxide, was successfully operated at a pressure of 54 atm, and in the LR87-11 model the pressure was brought to 59 atm! Same tubes, same camera, but what's the difference? The difference is simple: firstly, aerosin-50 (a mixture of heptyl and hydrazine) in nitrogen tetroxide burns at a temperature a couple of hundred degrees lower,and secondly, hydrazine and its derivatives have better cooling properties than kerosene.
To tell the truth, of all the fuel components used in astronautics, kerosene is in last place as a coolant. If anyone is interested in Soviet liquid-propellant rocket engines with a pressure deep beyond 100 atm in the chamber, then I will explain a simple thing: there, in addition to flow cooling, there are two or three more curtain cooling belts by direct fuel injection into the wall layer. It's just that it is possible to organize fuel injection belts in a sheet casing, but not in a tubular chamber! The tubular structure itself serves as a hindrance. Having completed this whole long excursion, the reader puzzled with a banal fact: in the "tubular" F-1 engine, a pressure of 70 atmospheres was allegedly realized! The trouble is that all tubular chambers made of nickel and steel materials above 40..48 atm at that time simply could not be realized. Otherwise, the Americans would have forced all their kerosene rocket engines long ago,which, according to the technological level, remained at the level of 40-50 years ago. However, I will try to devote a separate special article to this aspect somehow.
I foresee (in advance) an argument of this kind: with a linear increase in the size of the engine, its surface grows in a square, and its volume in a cube. Let's say the linear dimension doubles, the engine surface area quadruples, and the volume grows eight times. And great! Just what follows from this? The fact is that the radiant heat flux is determined by the emitting surface of the gas, and not by its volume (luminosity, in principle, is defined as the radiated power by a unit area), also with the convective heat flux - it is determined by the surface area of the chamber, and not by its volume. The only thing that is growing in our country is the specific proportion of kerosene, which can be used to cool a unit of area of the chamber wall. But the trouble is - even if we pump twice as much kerosene, the cooling capacity of the wall itself will not increase from this, and it will not be able to give more heat. Moreover, no regenerative cooling of kerosene liquid-propellant rocket engines is in principle capable of removing all heat flows from the body without using the already mentioned curtain cooling by direct injection into the wall layer, which (due to the tubular nature of the chamber) cannot be organized except near the head.
If this were not the case, now the Soviet (Russian) RD-180s with a pressure of 250 atm in a chamber with a sheet chrome-bronze jacket and a multi-tiered curtain cooling would not be used on American Atlas, but on the contrary - on our Soyuz and "Protons" would be licensed tubular-nickel monsters such as F-1 and others like them. Therefore, based on the above, the thrust of the F-1 rocket engine should be proportionally "sequestered" to the operating pressure level of 40..48 atm or 30..40% of the nominal value, i.e. to the level of 380..460 tons near the ground, which sharply reduces the total estimated mass of the Saturn-5 rocket by more than one and a half times! Moving in this direction, and comparing this hypothesis with the study of newsreels of the flight "Saturn-5", S. Pokrovsky came to the conclusion,that the nature of the supersonic shock waves indicates a significant underspeed in the section of the first stage operation, which confirms the insufficient thrust of the engines and a significantly reduced fuel supply. And although a dispute is possible regarding the estimates of the real flight speed of the Saturn-5 rocket, one thing is certain - its first stage was significantly (perhaps twice) lighter than the canonical version, otherwise this design would never have been able to break away from the launch pad.
Part 1 - Part 3