The first stage is denial

German rocketry expert Robert Schmucker considered V. Putin's statements completely implausible. “I can’t imagine that the Russians can create a small flying reactor,” the expert said in an interview with Deutsche Welle.

They can, Herr Schmucker. Just imagine.

The first domestic satellite with a nuclear power plant (“Cosmos-367”) was launched from Baikonur back in 1970. 37 fuel assemblies of the small-sized BES-5 Buk reactor, containing 30 kg of uranium, at a temperature in the primary circuit of 700 ° C and a heat release of 100 kW, provided an electrical power of the installation of 3 kW. The weight of the reactor is less than one ton, the estimated operating time is 120-130 days.

Experts will express doubt: the power of this nuclear “battery” is too low... But! Look at the date: that was half a century ago.

Low efficiency is a consequence of thermionic conversion. With other forms of energy transmission, the indicators are much higher, for example, for nuclear power plants, the efficiency value is in the range of 32-38%. In this sense, the thermal power of a “space” reactor is of particular interest. 100 kW is a serious bid for victory.

It is worth noting that the BES-5 “Buk” does not belong to the family of RTGs. Radioisotope thermoelectric generators convert the energy of the natural decay of atoms of radioactive elements and have negligible power. At the same time, Buk is a real reactor with a controlled chain reaction.

The next generation of Soviet small-sized reactors, which appeared in the late 1980s, was distinguished by even smaller dimensions and higher energy release. This was the unique Topaz: compared to the Buk, the amount of uranium in the reactor was reduced threefold (to 11.5 kg). Thermal power increased by 50% and amounted to 150 kW, the continuous operation time reached 11 months (a reactor of this type was installed on board the Cosmos-1867 reconnaissance satellite).

Nuclear space reactors are an extraterrestrial form of death. If control was lost, the “shooting star” did not fulfill wishes, but could forgive the “lucky” ones their sins.

In 1992, the two remaining copies of small-sized reactors of the Topaz series were sold in the USA for $13 million.

The main question is: do such installations have enough power to be used as rocket engines? By passing the working fluid (air) through the hot core of the reactor and obtaining thrust at the output according to the law of conservation of momentum.

Answer: no. “Buk” and “Topaz” are compact nuclear power plants. To create a nuclear reactor, other means are needed. But the general trend is visible to the naked eye. Compact nuclear power plants have long been created and exist in practice.

What power must a nuclear power plant have to be used as a propulsion engine for a cruise missile similar in size to the X-101?

Can't find a job? Multiply time by power!
(Collection of universal tips.)

Finding power is also not difficult. N=F×V.

According to official data, the Kha-101 cruise missiles, like the Kalibr family of missiles, are equipped with a short-life turbofan engine-50, developing a thrust of 450 kgf (≈ 4400 N). The cruise missile's cruising speed is 0.8M, or 270 m/s. The ideal calculated efficiency of a turbojet bypass engine is 30%.

In this case, the required power of the cruise missile engine is only 25 times higher than the thermal power of the Topaz series reactor.

Despite the doubts of the German expert, the creation of a nuclear turbojet (or ramjet) rocket engine is a realistic task that meets the requirements of our time.

Rocket from Hell

"This is all a surprise - a nuclear-powered cruise missile," said Douglas Barry, a senior fellow at the International Institute for Strategic Studies in London. “This idea is not new, it was talked about in the 60s, but it has faced a lot of obstacles.”

They didn't just talk about it. During tests in 1964, the Tori-IIC nuclear ramjet engine developed a thrust of 16 tons with a reactor thermal power of 513 MW. Simulating supersonic flight, the installation consumed 450 tons of compressed air in five minutes. The reactor was designed to be very “hot” - the operating temperature in the core reached 1600°C. The design had very narrow tolerances: in a number of areas, the permissible temperature was only 150-200 ° C below the temperature at which the rocket elements melted and collapsed.

Were these indicators sufficient to use nuclear-propelled jet engines as an engine in practice? The answer is obvious.

The nuclear ramjet developed more (!) thrust than the turbo-ramjet engine of the “three-mach” reconnaissance aircraft SR-71 “Black Bird”.

"Polygon-401", nuclear ramjet tests

Experimental installations “Tori-IIA” and “-IIC” are prototypes of the nuclear engine of the SLAM cruise missile.

A diabolical invention, capable, according to calculations, of piercing 160,000 km of space at a minimum altitude at a speed of 3M. Literally “mowing down” everyone who met on her mournful path with a shock wave and a thunderclap of 162 dB (lethal value for humans).

The reactor of the combat aircraft did not have any biological protection. The ruptured eardrums after the SLAM flyby would seem insignificant compared to the radioactive emissions from the rocket nozzle. The flying monster left behind a trail more than a kilometer wide with a radiation dose of 200-300 rad. It is estimated that SLAM contaminated 1,800 square miles with deadly radiation in one hour of flight.

According to calculations, the length of the aircraft could reach 26 meters. Launch weight - 27 tons. The combat load was thermonuclear charges, which had to be dropped sequentially on several Soviet cities along the missile’s flight route. After completing the main task, SLAM was supposed to circle over the territory of the USSR for several more days, contaminating everything around with radioactive emissions.

Perhaps the deadliest of all that man has tried to create. Fortunately, it didn’t come to real launches.

The project, codenamed “Pluto,” was canceled on July 1, 1964. At the same time, according to one of the developers of SLAM, J. Craven, none of the US military and political leadership regretted the decision.

The reason for abandoning the “low-flying nuclear missile” was the development of intercontinental ballistic missiles. Capable of causing the necessary damage in less time with incomparable risks for the military themselves. As the authors of the publication in Air&Space magazine rightly noted: ICBMs, at least, did not kill everyone who was near the launcher.

It is still unknown who, where and how planned to test the fiend. And who would be responsible if SLAM went off course and flew over Los Angeles. One of the crazy proposals suggested tying a rocket to a cable and driving it in a circle over deserted areas of the state. Nevada. However, another question immediately arose: what to do with the rocket when the last remnants of fuel burn out in the reactor? The place where the SLAM “lands” will not be approached for centuries.

Life or death. Final choice

Unlike the mystical “Pluto” from the 1950s, the project of a modern nuclear missile, voiced by V. Putin, proposes the creation of an effective means of breaking through the American missile defense system. Mutually assured destruction is the most important criterion for nuclear deterrence.

Transforming the classic “nuclear triad” into a diabolical “pentagram” - with the inclusion of a new generation of delivery vehicles (nuclear cruise missiles of unlimited range and strategic nuclear torpedoes “status-6”), coupled with the modernization of ICBM warheads (maneuvering “Avangard”), is reasonable response to the emergence of new threats. Washington's missile defense policy leaves Moscow no other choice.

“You are developing your anti-missile systems. The range of anti-missiles is increasing, the accuracy is increasing, these weapons are being improved. Therefore, we need to adequately respond to this so that we can overcome the system not only today, but also tomorrow, when you have new weapons.”

V. Putin in an interview with NBC.

The declassified details of the experiments under the SLAM/Pluto program convincingly prove that the creation of a nuclear cruise missile was possible (technically feasible) six decades ago. Modern technologies allow us to take an idea to a new technical level.

The sword rusts from promises

Despite the mass of obvious facts that explain the reasons for the appearance of the “presidential superweapon” and dispel any doubts about the “impossibility” of creating such systems, there are still many skeptics in Russia, as well as abroad. “All of the weapons listed are just a means of information warfare.” And then - a variety of proposals.

Probably, one should not take caricatured “experts” such as I. Moiseev seriously. The head of the Space Policy Institute (?), who told the online publication The Insider: “You cannot put a nuclear engine on a cruise missile. And there are no such engines.”

Attempts to “expose” the president’s statements are also being made at a more serious analytical level. Such “investigations” immediately gain popularity among the liberal-minded public. Skeptics give the following arguments.

All the announced systems relate to strategic top-secret weapons, the existence of which is not possible to verify or refute. (The message to the Federal Assembly itself showed computer graphics and footage of launches, indistinguishable from tests of other types of cruise missiles.) At the same time, no one is talking, for example, about creating a heavy attack drone or a destroyer-class warship. A weapon that would soon have to be clearly demonstrated to the whole world.

According to some “whistleblowers,” the highly strategic, “secret” context of the messages may indicate their implausible nature. Well, if this is the main argument, then what is the argument with these people about?

There is also another point of view. Shocking statements about nuclear missiles and unmanned 100-knot submarines are made against the background of obvious problems of the military-industrial complex encountered in the implementation of simpler projects of “traditional” weapons. Statements about missiles that immediately surpass all existing weapons are in sharp contrast to the well-known situation with rocket science. Skeptics cite the example of massive failures during Bulava launches or the development of the Angara launch vehicle, which dragged on for two decades. Sama began in 1995; speaking in November 2017, Deputy Prime Minister D. Rogozin promised to resume Angara launches from the Vostochny cosmodrome only in... 2021.

And, by the way, why was Zircon, the main naval sensation of the previous year, left without attention? A hypersonic missile capable of destroying all existing concepts of naval combat.

The news about the arrival of laser systems to the troops attracted the attention of manufacturers of laser systems. Existing directed energy weapons were created on an extensive base of research and development of high-tech equipment for the civilian market. For example, the American shipborne installation AN/SEQ-3 LaWS is a “pack” of six welding lasers with a total power of 33 kW.

The announcement of the creation of a super-powerful combat laser contrasts against the background of a very weak laser industry: Russia is not one of the world's largest manufacturers of laser equipment (Coherent, IPG Photonics or the Chinese Han "Laser Technology). Therefore, the sudden appearance of high-power laser weapons arouses genuine interest among specialists .

There are always more questions than answers. The devil is in the details, but official sources give an extremely poor picture of the latest weapons. It is often not even clear whether the system is already ready for adoption, or whether its development is at a certain stage. Well-known precedents associated with the creation of such weapons in the past indicate that the problems that arise cannot be solved with a snap of the fingers. Fans of technical innovations are concerned about the choice of location for testing nuclear-powered missile launchers. Or methods of communication with the underwater drone “Status-6” (a fundamental problem: radio communication does not work under water; during communication sessions, submarines are forced to rise to the surface). It would be interesting to hear an explanation about the methods of application: compared to traditional ICBMs and SLBMs, capable of starting and ending a war within an hour, Status-6 will take several days to reach the US coast. When there will be no one there anymore!

The last battle is over.
Is anyone left alive?
In response - only the howling of the wind...

Using materials:
Air&Space Magazine (April-May 1990)
The Silent War by John Craven

IN one of the sections On LiveJournal, an electronics engineer constantly writes about nuclear and thermonuclear machines - reactors, installations, research laboratories, accelerators, as well as about. The new Russian missile, testimony during the annual presidential address, aroused the keen interest of the blogger. And this is what he found on this topic.

Yes, historically there have been developments of cruise missiles with a ramjet nuclear air engine: the SLAM missile in the USA with the TORY-II reactor, the Avro Z-59 concept in the UK, developments in the USSR.

A modern rendering of the Avro Z-59 rocket concept, weighing about 20 tons.

However, all this work was carried out in the 60s as R&D of varying degrees of depth (the United States went the furthest, as discussed below) and was not continued in the form of models in service. We didn’t get it for the same reason as many other Atom Age developments - planes, trains, missiles with nuclear power plants. All these vehicle options, with some advantages provided by the insane energy density in nuclear fuel, have very serious disadvantages - high cost, complexity of operation, requirements for constant security, and finally, unsatisfactory development results, about which little is usually known (by publishing the results of R&D it is more profitable for all parties display achievements and hide failures).

In particular, for cruise missiles it is much easier to create a carrier (submarine or aircraft) that will “drag” many missile launchers to the launch site than to fool around with a small fleet (and it is incredibly difficult to develop a large fleet) of cruise missiles launched from one’s own territory. A universal, cheap, mass-produced product ultimately won out over a small-scale, expensive product with ambiguous advantages. Nuclear cruise missiles have not gone beyond ground testing.

This conceptual dead end of the 60s of the Kyrgyz Republic with nuclear power plants, in my opinion, is still relevant now, so the main question to the one shown is “why??”. But what makes it even more prominent are the problems that arise during the development, testing and operation of such weapons, which we will discuss further.

So, let's start with the reactor. The SLAM and Z-59 concepts were three-mach low-flying rockets of impressive size and weight (20+ tons after the launch boosters were jettisoned). The terribly expensive low-flying supersonic made it possible to make maximum use of the presence of a practically unlimited source of energy on board; in addition, an important feature of the nuclear air jet engine is improved operating efficiency (thermodynamic cycle) with increasing speed, i.e. the same idea, but at speeds of 1000 km/h it would have a much heavier and larger engine. Finally, 3M at an altitude of a hundred meters in 1965 meant invulnerability to air defense. It turns out that earlier the concept of missile launchers with nuclear power was “tied up” at high speed, where the advantages of the concept were strong, and competitors with hydrocarbon fuel were weakening. The shown rocket, in my opinion look, transonic or subsonic (if, of course, you believe that it is she in the video). But at the same time, the size of the reactor has decreased significantly compared to TORY-II from the SLAM rocket, where it was as much as 2 meters including the radial neutron reflector made of graphite

Is it even possible to install a reactor with a diameter of 0.4-0.6 meters?

Let's start with a fundamentally minimal reactor - a Pu239 pig. A good example of the implementation of such a concept is the Kilopower space reactor, which, however, uses U235. The diameter of the reactor core is only 11 centimeters! If we switch to plutonium 239, the size of the core will drop by another 1.5-2 times. Now from the minimum size we will begin to step towards a real nuclear air jet engine, remembering the difficulties.

The very first thing to add to the size of the reactor is the size of the reflector - in particular, in Kilopower BeO triples the size. Secondly, we cannot use U or Pu blanks - they will simply burn out in the air flow in just a minute. A shell is needed, for example from incaloy, which resists instant oxidation up to 1000 C, or other nickel alloys with a possible ceramic coating. The introduction of a large amount of shell material into the core increases the required amount of nuclear fuel several times at once - after all, the “unproductive” absorption of neutrons in the core has now increased sharply!

Moreover, the metal form of U or Pu is no longer suitable - these materials themselves are not refractory (plutonium generally melts at 634 C), and they also interact with the material of the metal shells. We convert the fuel into the classical form of UO2 or PuO2 - we get another dilution of the material in the core, this time with oxygen.

Finally, let's remember the purpose of the reactor. We need to pump a lot of air through it, to which we will give off heat. Approximately 2/3 of the space will be occupied by “air tubes”.

As a result, the minimum diameter of the core grows to 40-50 cm (for uranium), and the diameter of the reactor with a 10-centimeter beryllium reflector to 60-70 cm. My knee-jerk estimates “by analogy” are confirmed by the design of a nuclear jet engine MITEE , designed for flights in the atmosphere of Jupiter. This completely paper project (for example, the core temperature is assumed to be 3000 K, and the walls are made of beryllium, which can withstand at most 1200 K) has a core diameter calculated from neutronics of 55.4 cm, despite the fact that cooling with hydrogen makes it possible to slightly reduce the size of the channels through which the coolant is pumped .

In my opinion, an airborne nuclear jet engine can be shoved into a rocket with a diameter of about a meter, which, however, is still not radically larger than the stated 0.6-0.74 m, but is still alarming. One way or another, the nuclear power plant will have a power of ~several megawatt, powered by ~10^16 decays per second. This means that the reactor itself will create a radiation field of several tens of thousands of roentgens at the surface, and up to a thousand roentgens along the entire rocket. Even installing several hundred kg of sector protection will not significantly reduce these levels, because Neutron and gamma rays will be reflected from the air and “bypass the protection.”

In a few hours, such a reactor will produce ~10^21-10^22 atoms of fission products c with an activity of several (several tens) petabecquerels, which even after shutdown will create a background of several thousand roentgens near the reactor.

The rocket design will be activated to about 10^14 Bq, although the isotopes will be primarily beta emitters and are only dangerous by bremsstrahlung X-rays. The background from the structure itself can reach tens of roentgens at a distance of 10 meters from the rocket body.

All this “fun” gives the idea that the development and testing of such a rocket is a task on the verge of the possible. It is necessary to create a whole set of radiation-resistant navigation and control equipment, to test it all in a fairly comprehensive way (radiation, temperature, vibration - and all this for statistics). Flight tests with a working reactor can at any moment turn into a radiation disaster with a release of hundreds of terrabecquerels to several petabecquerels. Even without catastrophic situations, depressurization of individual fuel elements and the release of radionuclides are very likely.

Of course, in Russia there are still Novozemelsky test site on which such tests can be carried out, but this would be contrary to the spirit of the agreement on banning nuclear weapons testing in three environments (the ban was introduced in order to prevent systematic pollution of the atmosphere and ocean by radionuclides).

Finally, I wonder who in the Russian Federation could develop such a reactor. Traditionally, the Kurchatov Institute (general design and calculations), Obninsk IPPE (experimental testing and fuel), and the Luch Research Institute in Podolsk (fuel and materials technology) were initially involved in high-temperature reactors. Later, the NIKIET team became involved in the design of such machines (for example, the IGR and IVG reactors are prototypes of the core of the RD-0410 nuclear rocket engine).

Today NIKIET has a team of designers who carry out work on reactor design ( high-temperature gas-cooled RUGK , fast reactors MBIR, ), and IPPE and Luch continue to engage in related calculations and technologies, respectively. In recent decades, the Kurchatov Institute has moved more toward the theory of nuclear reactors.

In summary, I would like to say that the creation of a cruise missile with air-jet engines with a nuclear power plant is generally a feasible task, but at the same time extremely expensive and complex, requiring a significant mobilization of human and financial resources, it seems to me to a greater extent than all other announced projects (" Sarmat", "Dagger", "Status-6", "Vanguard"). It is very strange that this mobilization did not leave the slightest trace. And most importantly, it is completely unclear what the benefits of obtaining such types of weapons (against the background of existing carriers) are, and how they can outweigh the numerous disadvantages - issues of radiation safety, high cost, incompatibility with strategic arms reduction treaties.

P.S. However, “sources” are already beginning to soften the situation: “A source close to the military-industrial complex said “ Vedomosti "that radiation safety was ensured during rocket testing. The nuclear installation on board was represented by an electrical mock-up, the source says.

03-03-2018

Valery Lebedev (review)

• In history, there have already been developments of cruise missiles with a ramjet nuclear air engine: this is the SLAM rocket (aka Pluto) in the USA with the TORY-II reactor (1959), the Avro Z-59 concept in the UK, developments in the USSR.
• Let's touch on the principle of operation of a rocket with a nuclear reactor. We are only talking about a ramjet nuclear engine, which was precisely what Putin had in mind in his speech about a cruise missile with an unlimited flight range and complete invulnerability. The atmospheric air in this rocket is heated by the nuclear assembly to high temperatures and is ejected from the rear nozzle at high speed. Tested in Russia (in the 60s) and among the Americans (since 1959). It has two significant drawbacks: 1. It stinks like the same nuclear bomb, so during the flight everything on the trajectory will be clogged. 2. In the thermal range it stinks so much that even a North Korean satellite with radio tubes can see it from space. Accordingly, you can knock down such a flying kerosene stove with complete confidence.
  So the cartoons shown in the Manege led to bewilderment, which grew into concern about the (mental) health of the director of this garbage.
  In Soviet times, such pictures (posters and other pleasures for generals) were called “Cheburashkas”.

  In general, this is a conventional straight-through design, axisymmetric with a streamlined central body and shell. The shape of the central body is such that, due to shock waves at the inlet, the air is compressed (the operating cycle starts at a speed of 1 M and higher, to which it is accelerated by a starting accelerator using conventional solid fuel);
  - inside the central body there is a nuclear heat source with a monolithic core;
  - the central body is connected to the shell by 12-16 plate radiators, where heat is removed from the core by heat pipes. The radiators are located in the expansion zone in front of the nozzle;
  - material of radiators and central body, for example, VNDS-1, which maintains structural strength up to 3500 K in the limit;
  - to be sure, we heat it up to 3250 K. The air, flowing around the radiators, heats up and cools them. It then passes through the nozzle, creating thrust;
  - to cool the shell to acceptable temperatures, we build an ejector around it, which at the same time increases thrust by 30-50%.

  An encapsulated monolithic nuclear power plant unit can either be installed in the housing before launch, or kept in a subcritical state until launch, and the nuclear reaction can be started if necessary. I don’t know how exactly, this is an engineering problem (and therefore amenable to solution). So this is clearly a weapon of the first strike, don’t go to grandma.
  An encapsulated nuclear power unit can be made in such a way that it is guaranteed not to be destroyed upon impact in the event of an accident. Yes, it will turn out to be heavy - but it will turn out to be heavy in any case.

  To reach hypersound, you will need to allocate a completely indecent energy density per unit time to the working fluid. With a 9/10 probability, existing materials will not be able to handle this over long periods of time (hours/days/weeks), the rate of degradation will be insane.

  And in general, the environment there will be aggressive. Protection from radiation is heavy, otherwise all the sensors/electronics can be thrown into a landfill at once (those interested can remember Fukushima and the questions: “why weren’t robots given the job of cleaning?”).

  Etc.... Such a prodigy will “glow” significantly. It is not clear how to transmit control commands to it (if everything is completely screened there).

  Let's touch on authentically created missiles with a nuclear power plant - an American design - the SLAM missile with the TORY-II reactor (1959).

  Here is this engine with a reactor:

  The SLAM concept was a three-mach low-flying rocket of impressive dimensions and weight (27 tons, 20+ tons after the launch boosters were jettisoned). The terribly expensive low-flying supersonic made it possible to make maximum use of the presence of a practically unlimited source of energy on board; in addition, an important feature of a nuclear air jet engine is the improvement of operating efficiency (thermodynamic cycle) with increasing speed, i.e. the same idea, but at speeds of 1000 km/h it would have a much heavier and larger engine. Finally, 3M at an altitude of a hundred meters in 1965 meant invulnerability to air defense.

  

  Engine TORY-IIC. The fuel elements in the active zone are hexagonal hollow tubes made of UO2, covered with a protective ceramic shell, assembled in incalo fuel assemblies.

  It turns out that previously the concept of a Cruise Missile with a nuclear power plant was “tied up” at high speed, where the advantages of the concept were strong, and competitors with hydrocarbon fuel were weakening.

• Video about the old American SLAM rocket

• The missile shown at Putin’s presentation is transonic or weakly supersonic (if, of course, you believe that it is the one in the video). But at the same time, the size of the reactor decreased significantly compared to TORY-II from the SLAM rocket, where it was as much as 2 meters including the radial neutron reflector made of graphite.
  Diagram of the SLAM rocket. All drives are pneumatic, the control equipment is located in a radiation-attenuating capsule.

  Is it even possible to install a reactor with a diameter of 0.4-0.6 meters? Let's start with a fundamentally minimal reactor - a Pu239 pig. A good example of the implementation of such a concept is the Kilopower space reactor, which, however, uses U235. The diameter of the reactor core is only 11 centimeters! If we switch to plutonium 239, the size of the core will drop by another 1.5-2 times.
  Now from the minimum size we will begin to step towards a real nuclear air jet engine, remembering the difficulties. The very first thing to add to the size of the reactor is the size of the reflector - in particular, in Kilopower BeO triples the size. Secondly, we cannot use U or Pu blanks - they will simply burn out in the air flow in just a minute. A shell is needed, for example from incaloy, which resists instant oxidation up to 1000 C, or other nickel alloys with a possible ceramic coating. The introduction of a large amount of shell material into the core increases the required amount of nuclear fuel several times at once - after all, the “unproductive” absorption of neutrons in the core has now increased sharply!
  Moreover, the metal form of U or Pu is no longer suitable - these materials themselves are not refractory (plutonium generally melts at 634 C), and they also interact with the material of the metal shells. We convert the fuel into the classical form of UO2 or PuO2 - we get another dilution of the material in the core, this time with oxygen.

  Finally, let's remember the purpose of the reactor. We need to pump a lot of air through it, to which we will give off heat. approximately 2/3 of the space will be occupied by “air tubes”. As a result, the minimum diameter of the core grows to 40-50 cm (for uranium), and the diameter of the reactor with a 10-centimeter beryllium reflector to 60-70 cm.

  An airborne nuclear jet engine can be shoved into a rocket with a diameter of about a meter, which, however, is still not radically larger than the stated 0.6-0.74 m, but is still alarming.

  One way or another, the nuclear power plant will have a power of ~several megawatts, powered by ~10^16 decays per second. This means that the reactor itself will create a radiation field of several tens of thousands of roentgens at the surface, and up to a thousand roentgens along the entire rocket. Even installing several hundred kg of sector protection will not significantly reduce these levels, because Neutron and gamma rays will be reflected from the air and “bypass the protection.” In a few hours, such a reactor will produce ~10^21-10^22 atoms of fission products with an activity of several (several tens) petabecquerels, which even after shutdown will create a background of several thousand roentgens near the reactor. The rocket design will be activated to about 10^14 Bq, although the isotopes will be primarily beta emitters and are only dangerous by bremsstrahlung X-rays. The background from the structure itself can reach tens of roentgens at a distance of 10 meters from the rocket body.

  All these difficulties give the idea that the development and testing of such a missile is a task on the verge of the possible. It is necessary to create a whole set of radiation-resistant navigation and control equipment, to test it all in a fairly comprehensive way (radiation, temperature, vibration - and all this for statistics). Flight tests with a working reactor can at any moment turn into a radiation disaster with a release of hundreds of terrabecquerels to several petabecquerels. Even without catastrophic situations, depressurization of individual fuel elements and the release of radionuclides are very likely.
  Because of all these difficulties, the Americans abandoned the SLAM nuclear-powered rocket in 1964.

  Of course, in Russia there is still the Novaya Zemlya test site where such tests can be carried out, but this will contradict the spirit of the treaty banning nuclear weapons tests in three environments (the ban was introduced to prevent systematic pollution of the atmosphere and ocean with radionuclides).

  Finally, I wonder who in the Russian Federation could develop such a reactor. Traditionally, the Kurchatov Institute (general design and calculations), Obninsk IPPE (experimental testing and fuel), and the Luch Research Institute in Podolsk (fuel and materials technology) were initially involved in high-temperature reactors. Later, the NIKIET team became involved in the design of such machines (for example, the IGR and IVG reactors are prototypes of the core of the RD-0410 nuclear rocket engine). Today NIKIET has a team of designers who carry out work on the design of reactors (high-temperature gas-cooled RUGK, fast reactors MBIR), and IPPE and Luch continue to engage in related calculations and technologies, respectively. In recent decades, the Kurchatov Institute has moved more toward the theory of nuclear reactors.

  To summarize, we can say that the creation of a cruise missile with air jet engines with a nuclear power plant is generally a feasible task, but at the same time extremely expensive and complex, requiring a significant mobilization of human and financial resources, it seems to me to a greater extent than all other announced projects (" Sarmat", "Dagger", "Status-6", "Vanguard"). It is very strange that this mobilization did not leave the slightest trace. And most importantly, it is completely unclear what the benefits of obtaining such types of weapons (against the background of existing carriers) are, and how they can outweigh the numerous disadvantages - issues of radiation safety, high cost, incompatibility with strategic arms reduction treaties.

  The small-sized reactor has been developed since 2010, Kiriyenko reported about this in the State Duma. It was assumed that it would be installed on a spacecraft with an electric propulsion system for flights to the Moon and Mars and tested in orbit this year.
  Obviously, a similar device is used for cruise missiles and submarines.

  Yes, it is possible to install a nuclear engine, and successful 5-minute tests of a 500 megawatt engine, made in the states many years ago for a cruise missile with a ram jet for a speed of Mach 3, in general, confirmed this (Project Pluto). Bench tests, of course (the engine was “blown” with prepared air of the required pressure/temperature). But why? Existing (and projected) ballistic missiles are sufficient for nuclear parity. Why create a weapon that is potentially more dangerous (for “our own people”) to use (and test)? Even in the Pluto project it was implied that such a missile flies over its territory at a considerable altitude, descending to sub-radar altitudes only close to enemy territory. It's not very good to be next to an unprotected 500 megawatt air-cooled uranium reactor with materials temperatures over 1300 Celsius. True, the mentioned rockets (if they are really being developed) will be less powerful than Pluto (Slam).
  Animation video from 2007, issued in Putin’s presentation for showing the latest cruise missile with a nuclear power plant.
  
  Perhaps all this is preparation for the North Korean version of blackmail. We will stop developing our dangerous weapons - and you will lift sanctions from us.
  What a week - the Chinese boss is pushing for lifelong rule, the Russian one is threatening the whole world.

Sergeev Alexey, 9 “A” class, Municipal Educational Institution “Secondary School No. 84”

Scientific consultant: , Deputy Director of the non-profit partnership for scientific and innovative activities "Tomsk Atomic Center"

Head: , physics teacher, Municipal Educational Institution “Secondary School No. 84” CATO Seversk

Introduction

Propulsion systems on board a spacecraft are designed to create thrust or momentum. According to the type of thrust used, the propulsion system is divided into chemical (CHRD) and non-chemical (NCRD). CRDs are divided into liquid propellant engines (LPRE), solid propellant rocket engines (solid propellant engines) and combined rocket engines (RCR). In turn, non-chemical propulsion systems are divided into nuclear (NRE) and electric (EP). The great scientist Konstantin Eduardovich Tsiolkovsky a century ago created the first model of a propulsion system that ran on solid and liquid fuel. Afterwards, in the second half of the 20th century, thousands of flights were carried out using mainly liquid propellant engines and solid propellant rocket engines.

However, at present, for flights to other planets, not to mention the stars, the use of liquid propellant rocket engines and solid propellant rocket engines is becoming increasingly unprofitable, although many rocket engines have been developed. Most likely, the capabilities of liquid propellant rocket engines and solid propellant rocket engines have completely exhausted themselves. The reason here is that the specific impulse of all chemical thrusters is low and does not exceed 5000 m/s, which requires long-term operation of the thruster and, accordingly, large reserves of fuel for the development of sufficiently high speeds, or, as is customary in astronautics, large values ​​of the Tsiolkovsky number are required, t i.e. the ratio of the mass of a fueled rocket to the mass of an empty one. Thus, the Energia launch vehicle, which launches 100 tons of payload into low orbit, has a launch mass of about 3,000 tons, which gives the Tsiolkovsky number a value within 30.

For a flight to Mars, for example, the Tsiolkovsky number should be even higher, reaching values ​​from 30 to 50. It is easy to estimate that with a payload of about 1,000 tons, and it is within these limits that the minimum mass required to provide everything necessary for the crew starting to Mars varies Taking into account the fuel supply for the return flight to Earth, the initial mass of the spacecraft must be at least 30,000 tons, which is clearly beyond the level of development of modern astronautics, based on the use of liquid propellant engines and solid propellant rocket engines.

Thus, in order for manned crews to reach even the nearest planets, it is necessary to develop launch vehicles on engines operating on principles other than chemical propulsion. The most promising in this regard are electric jet engines (EPE), thermochemical rocket engines and nuclear jet engines (NRE).

1.Basic concepts

A rocket engine is a jet engine that does not use the environment (air, water) for operation. Chemical rocket engines are the most widely used. Other types of rocket engines are being developed and tested - electric, nuclear and others. The simplest rocket engines running on compressed gases are also widely used on space stations and vehicles. Typically, they use nitrogen as a working fluid. /1/

Classification of propulsion systems

2. Purpose of rocket engines

According to their purpose, rocket engines are divided into several main types: accelerating (starting), braking, propulsion, control and others. Rocket engines are primarily used on rockets (hence the name). In addition, rocket engines are sometimes used in aviation. Rocket engines are the main engines in astronautics.

Military (combat) missiles usually have solid propellant motors. This is due to the fact that such an engine is refueled at the factory and does not require maintenance for the entire storage and service life of the rocket itself. Solid propellant engines are often used as boosters for space rockets. They are used especially widely in this capacity in the USA, France, Japan and China.

Liquid rocket engines have higher thrust characteristics than solid rocket engines. Therefore, they are used to launch space rockets into orbit around the Earth and for interplanetary flights. The main liquid propellants for rockets are kerosene, heptane (dimethylhydrazine) and liquid hydrogen. For such types of fuel, an oxidizer (oxygen) is required. Nitric acid and liquefied oxygen are used as oxidizers in such engines. Nitric acid is inferior to liquefied oxygen in terms of oxidizing properties, but does not require maintaining a special temperature regime during storage, refueling and use of missiles

Engines for space flights differ from those on Earth in that they must produce as much power as possible with the smallest possible mass and volume. In addition, they are subject to such requirements as exceptionally high efficiency and reliability, and significant operating time. Based on the type of energy used, spacecraft propulsion systems are divided into four types: thermochemical, nuclear, electric, solar-sail. Each of the listed types has its own advantages and disadvantages and can be used in certain conditions.

Currently, spaceships, orbital stations and unmanned Earth satellites are launched into space by rockets equipped with powerful thermochemical engines. There are also miniature engines with low thrust. This is a smaller copy of powerful engines. Some of them can fit in the palm of your hand. The thrust force of such engines is very small, but it is enough to control the position of the ship in space

3.Thermochemical rocket engines.

It is known that in an internal combustion engine, the furnace of a steam boiler - wherever combustion occurs, atmospheric oxygen takes the most active part. There is no air in outer space, and for rocket engines to operate in outer space, it is necessary to have two components - fuel and oxidizer.

Liquid thermochemical rocket engines use alcohol, kerosene, gasoline, aniline, hydrazine, dimethylhydrazine, and liquid hydrogen as fuel. Liquid oxygen, hydrogen peroxide, and nitric acid are used as an oxidizing agent. Perhaps in the future liquid fluorine will be used as an oxidizing agent when methods for storing and using such an active chemical are invented

Fuel and oxidizer for liquid jet engines are stored separately in special tanks and supplied to the combustion chamber using pumps. When they are combined in the combustion chamber, temperatures reach 3000 – 4500 °C.

Combustion products, expanding, acquire speeds from 2500 to 4500 m/s. Pushing off from the engine body, they create jet thrust. At the same time, the greater the mass and speed of gas flow, the greater the thrust of the engine.

The specific thrust of engines is usually estimated by the amount of thrust created per unit mass of fuel burned in one second. This quantity is called the specific impulse of a rocket engine and is measured in seconds (kg thrust / kg burnt fuel per second). The best solid propellant rocket engines have a specific impulse of up to 190 s, that is, 1 kg of fuel burning in one second creates a thrust of 190 kg. A hydrogen-oxygen rocket engine has a specific impulse of 350 s. Theoretically, a hydrogen-fluorine engine can develop a specific impulse of more than 400 s.

The commonly used liquid rocket engine circuit works as follows. Compressed gas creates the necessary pressure in tanks with cryogenic fuel to prevent the occurrence of gas bubbles in pipelines. Pumps supply fuel to rocket engines. Fuel is injected into the combustion chamber through a large number of injectors. An oxidizer is also injected into the combustion chamber through the nozzles.

In any car, when fuel burns, large heat flows are formed that heat the walls of the engine. If you do not cool the walls of the chamber, it will quickly burn out, no matter what material it is made of. A liquid jet engine is typically cooled by one of the fuel components. For this purpose, the chamber is made of two walls. The cold component of the fuel flows in the gap between the walls.

Aluminum" href="/text/category/alyuminij/" rel="bookmark">aluminum, etc. Especially as an additive to conventional fuels, such as hydrogen-oxygen. Such “ternary compositions” can provide the highest speed possible for chemical fuels exhaust - up to 5 km/s. But this is practically the limit of the resources of chemistry. It practically cannot do more. Although the proposed description is still dominated by liquid rocket engines, it must be said that the first in the history of mankind was created a thermochemical rocket engine using solid fuel - Solid propellant rocket motor. Fuel - for example, special gunpowder - is located directly in the combustion chamber. A combustion chamber with a jet nozzle filled with solid fuel - that’s the whole design. The combustion mode of solid fuel depends on the purpose of the solid propellant rocket engine (launch, sustainer or combined). For solid fuel rockets used in military affairs are characterized by the presence of launch and propulsion engines.The launch solid propellant rocket engine develops high thrust for a very short time, which is necessary for the missile to leave the launcher and for its initial acceleration. The sustainer solid propellant rocket motor is designed to maintain a constant flight speed of the rocket on the main (propulsion) section of the flight path. The differences between them lie mainly in the design of the combustion chamber and the profile of the combustion surface of the fuel charge, which determine the rate of fuel combustion on which the operating time and engine thrust depend. Unlike such rockets, space launch vehicles for launching Earth satellites, orbital stations and spacecraft, as well as interplanetary stations operate only in the launch mode from the launch of the rocket until the object is launched into orbit around the Earth or onto an interplanetary trajectory. In general, solid propellant rocket engines do not have many advantages over liquid fuel engines: they are easy to manufacture, can be stored for a long time, are always ready for action, and are relatively explosion-proof. But in terms of specific thrust, solid fuel engines are 10-30% inferior to liquid engines.

4. Electric rocket engines

Almost all of the rocket engines discussed above develop enormous thrust and are designed to launch spacecraft into orbit around the Earth and accelerate them to cosmic speeds for interplanetary flights. A completely different matter is propulsion systems for spacecraft already launched into orbit or on an interplanetary trajectory. Here, as a rule, we need low-power motors (several kilowatts or even watts) capable of operating for hundreds and thousands of hours and being switched on and off repeatedly. They allow you to maintain flight in orbit or along a given trajectory, compensating for the flight resistance created by the upper layers of the atmosphere and the solar wind. In electric rocket engines, the working fluid is accelerated to a certain speed by heating it with electrical energy. Electricity comes from solar panels or a nuclear power plant. Methods for heating the working fluid are different, but in reality, electric arc is mainly used. It has proven to be very reliable and can withstand a large number of starts. Hydrogen is used as a working fluid in electric arc motors. Using an electric arc, hydrogen is heated to a very high temperature and it turns into plasma - an electrically neutral mixture of positive ions and electrons. The speed of plasma outflow from the engine reaches 20 km/s. When scientists solve the problem of magnetic isolation of plasma from the walls of the engine chamber, then it will be possible to significantly increase the temperature of the plasma and increase the exhaust speed to 100 km/s. The first electric rocket engine was developed in the Soviet Union in the years. under the leadership (later he became the creator of engines for Soviet space rockets and an academician) at the famous Gas Dynamics Laboratory (GDL)./10/

5.Other types of engines

There are also more exotic designs for nuclear rocket engines, in which the fissile material is in a liquid, gaseous or even plasma state, but the implementation of such designs at the current level of technology and technology is unrealistic. The following rocket engine projects exist, still at the theoretical or laboratory stage:

Pulse nuclear rocket engines using the energy of explosions of small nuclear charges;

Thermonuclear rocket engines, which can use a hydrogen isotope as fuel. The energy productivity of hydrogen in such a reaction is 6.8 * 1011 KJ/kg, that is, approximately two orders of magnitude higher than the productivity of nuclear fission reactions;

Solar-sail engines - which use the pressure of sunlight (solar wind), the existence of which was empirically proven by a Russian physicist back in 1899. By calculation, scientists have established that a device weighing 1 ton, equipped with a sail with a diameter of 500 m, can fly from Earth to Mars in about 300 days. However, the efficiency of a solar sail decreases rapidly with distance from the Sun.

6.Nuclear rocket engines

One of the main disadvantages of rocket engines running on liquid fuel is associated with the limited flow rate of gases. In nuclear rocket engines, it seems possible to use the colossal energy released during the decomposition of nuclear “fuel” to heat the working substance. The operating principle of nuclear rocket engines is almost no different from the operating principle of thermochemical engines. The difference is that the working fluid is heated not due to its own chemical energy, but due to “extraneous” energy released during an intranuclear reaction. The working fluid is passed through a nuclear reactor, in which the fission reaction of atomic nuclei (for example, uranium) occurs, and is heated. Nuclear rocket engines eliminate the need for an oxidizer and therefore only one liquid can be used. As a working fluid, it is advisable to use substances that allow the engine to develop greater traction force. This condition is most fully satisfied by hydrogen, followed by ammonia, hydrazine and water. The processes in which nuclear energy is released are divided into radioactive transformations, fission reactions of heavy nuclei, and fusion reactions of light nuclei. Radioisotope transformations are realized in so-called isotope energy sources. The specific mass energy (the energy that a substance weighing 1 kg can release) of artificial radioactive isotopes is significantly higher than that of chemical fuels. Thus, for 210Po it is equal to 5*10 8 KJ/kg, while for the most energy-efficient chemical fuel (beryllium with oxygen) this value does not exceed 3*10 4 KJ/kg. Unfortunately, it is not yet rational to use such engines on space launch vehicles. The reason for this is the high cost of the isotopic substance and operational difficulties. After all, the isotope constantly releases energy, even when it is transported in a special container and when the rocket is parked at the launch site. Nuclear reactors use more energy-efficient fuel. Thus, the specific mass energy of 235U (the fissile isotope of uranium) is equal to 6.75 * 10 9 KJ/kg, that is, approximately an order of magnitude higher than that of the 210Po isotope. These engines can be “switched on” and “switched off”; nuclear fuel (233U, 235U, 238U, 239Pu) is much cheaper than isotope fuel. In such engines, not only water can be used as a working fluid, but also more efficient working substances - alcohol, ammonia, liquid hydrogen. The specific thrust of an engine with liquid hydrogen is 900 s. In the simplest design of a nuclear rocket engine with a reactor running on solid nuclear fuel, the working fluid is placed in a tank. The pump supplies it to the engine chamber. Sprayed using nozzles, the working fluid comes into contact with the fuel-generating nuclear fuel, heats up, expands and is thrown out at high speed through the nozzle. Nuclear fuel is superior in energy reserves to any other type of fuel. Then a logical question arises: why do installations using this fuel still have a relatively low specific thrust and a large mass? The fact is that the specific thrust of a solid-phase nuclear rocket engine is limited by the temperature of the fissile material, and the power plant during operation emits strong ionizing radiation, which has a harmful effect on living organisms. Biological protection against such radiation is very important and is not applicable on spacecraft. Practical development of nuclear rocket engines using solid nuclear fuel began in the mid-50s of the 20th century in the Soviet Union and the USA, almost simultaneously with the construction of the first nuclear power plants. The work was carried out in an atmosphere of increased secrecy, but it is known that such rocket engines have not yet received real use in astronautics. Everything has so far been limited to the use of isotopic sources of electricity of relatively low power on unmanned artificial Earth satellites, interplanetary spacecraft and the world famous Soviet “lunar rover”.

7.Nuclear jet engines, operating principles, methods of obtaining impulse in a nuclear propulsion engine.

Nuclear rocket engines got their name due to the fact that they create thrust through the use of nuclear energy, that is, the energy that is released as a result of nuclear reactions. In a general sense, these reactions mean any changes in the energy state of atomic nuclei, as well as transformations of some nuclei into others, associated with a restructuring of the structure of nuclei or a change in the number of elementary particles contained in them - nucleons. Moreover, nuclear reactions, as is known, can occur either spontaneously (i.e. spontaneously) or caused artificially, for example, when some nuclei are bombarded by others (or elementary particles). Nuclear fission and fusion reactions exceed chemical reactions by millions and tens of millions of times in energy, respectively. This is explained by the fact that the chemical bond energy of atoms in molecules is many times less than the nuclear bond energy of nucleons in the nucleus. Nuclear energy in rocket engines can be used in two ways:

1. The released energy is used to heat the working fluid, which then expands in the nozzle, just like in a conventional rocket engine.

2. Nuclear energy is converted into electrical energy and then used to ionize and accelerate particles of the working fluid.

3. Finally, the impulse is created by the fission products themselves, formed in the process DIV_ADBLOCK265">

By analogy with a liquid-propellant rocket engine, the initial working fluid of the nuclear-propulsion engine is stored in a liquid state in the tank of the propulsion system and is supplied using a turbopump unit. The gas for rotating this unit, consisting of a turbine and a pump, can be produced in the reactor itself.

A diagram of such a propulsion system is shown in the figure.

There are many nuclear powered engines with a fission reactor:

Solid phase

Gas phase

NRE with fusion reactor

Pulse nuclear propulsion engines and others

Of all the possible types of nuclear propulsion engines, the most developed are the thermal radioisotope engine and the engine with a solid-phase fission reactor. But if the characteristics of radioisotope nuclear propulsion engines do not allow us to hope for their widespread use in astronautics (at least in the near future), then the creation of solid-phase nuclear propulsion engines opens up great prospects for astronautics. A typical nuclear propulsion engine of this type contains a solid-phase reactor in the form of a cylinder with a height and diameter of about 1-2 m (if these parameters are close, the leakage of fission neutrons into the surrounding space is minimal).

The reactor consists of a core; a reflector surrounding this area; governing bodies; power body and other elements. The core contains nuclear fuel - fissile material (enriched uranium) contained in fuel elements, and a moderator or diluent. The reactor shown in the figure is homogeneous - in it the moderator is part of the fuel elements, being homogeneously mixed with the fuel. The moderator can also be located separately from the nuclear fuel. In this case, the reactor is called heterogeneous. Diluents (they can be, for example, refractory metals - tungsten, molybdenum) are used to impart special properties to fissile substances.

The fuel elements of a solid-phase reactor are permeated with channels through which the working fluid of the nuclear propulsion engine flows, gradually heating up. The channels have a diameter of about 1-3 mm, and their total area is 20-30% of the cross-section of the active zone. The core is suspended by a special grid inside the power vessel so that it can expand when the reactor heats up (otherwise it would collapse due to thermal stresses).

The core experiences high mechanical loads associated with significant hydraulic pressure drops (up to several tens of atmospheres) from the flowing working fluid, thermal stresses and vibrations. The increase in the size of the active zone when the reactor heats up reaches several centimeters. The active zone and reflector are placed inside a durable power housing that absorbs the pressure of the working fluid and the thrust created by the jet nozzle. The case is closed with a durable lid. It houses pneumatic, spring or electric mechanisms for driving the regulatory bodies, attachment points for the nuclear propulsion engine to the spacecraft, and flanges for connecting the nuclear propulsion engine to the supply pipelines of the working fluid. A turbopump unit can also be located on the cover.

8 - Nozzle,

9 - Expanding nozzle nozzle,

10 - Selection of working substance for the turbine,

11 - Power Corps,

12 - Control drum,

13 - Turbine exhaust (used to control attitude and increase thrust),

14 - Drive ring for control drums)

At the beginning of 1957, the final direction of work at the Los Alamos Laboratory was determined, and a decision was made to build a graphite nuclear reactor with uranium fuel dispersed in graphite. The Kiwi-A reactor, created in this direction, was tested in 1959 on July 1st.

American solid phase nuclear jet engine XE Prime on a test bench (1968)

In addition to the construction of the reactor, the Los Alamos Laboratory was in full swing on the construction of a special test site in Nevada, and also carried out a number of special orders from the US Air Force in related areas (the development of individual TURE units). On behalf of the Los Alamos Laboratory, all special orders for the manufacture of individual components were carried out by the following companies: Aerojet General, the Rocketdyne division of North American Aviation. In the summer of 1958, all control of the Rover program was transferred from the United States Air Force to the newly organized National Aeronautics and Space Administration (NASA). As a result of a special agreement between the AEC and NASA in the mid-summer of 1960, the Space Nuclear Propulsion Office was formed under the leadership of G. Finger, which subsequently headed the Rover program.

The results obtained from six "hot tests" of nuclear jet engines were very encouraging, and in early 1961 a report on reactor flight testing (RJFT) was prepared. Then, in mid-1961, the Nerva project (the use of a nuclear engine for space rockets) was launched. Aerojet General was chosen as the general contractor, and Westinghouse was chosen as the subcontractor responsible for the construction of the reactor.

10.2 Work on TURE in Russia

American" href="/text/category/amerikanetc/" rel="bookmark">Americans, Russian scientists used the most economical and effective tests of individual fuel elements in research reactors. The entire range of work carried out in the 70-80s allowed the design bureau " Salyut", Design Bureau of Chemical Automatics, IAE, NIKIET and NPO "Luch" (PNITI) to develop various projects of space nuclear propulsion engines and hybrid nuclear power plants. In the Design Bureau of Chemical Automatics under the scientific leadership of NIITP (FEI, IAE, NIKIET, NIITVEL, NPO were responsible for the reactor elements Luch", MAI) were created YARD RD 0411 and nuclear engine of minimum size RD 0410 thrust 40 and 3.6 tons, respectively.

As a result, a reactor, a “cold” engine and a bench prototype were manufactured for testing on hydrogen gas. Unlike the American one, with a specific impulse of no more than 8250 m/s, the Soviet TNRE, due to the use of more heat-resistant and advanced design fuel elements and high temperature in the core, had this figure equal to 9100 m/s and higher. The bench base for testing the TURE of the joint expedition of NPO "Luch" was located 50 km southwest of the city of Semipalatinsk-21. She started working in 1962. In At the test site, full-scale fuel elements of nuclear-powered rocket engine prototypes were tested. In this case, the exhaust gas entered the closed exhaust system. The Baikal-1 test bench complex for full-size nuclear engine testing is located 65 km south of Semipalatinsk-21. From 1970 to 1988, about 30 “hot starts” of reactors were carried out. At the same time, the power did not exceed 230 MW with a hydrogen consumption of up to 16.5 kg/sec and its temperature at the reactor outlet of 3100 K. All launches were successful, trouble-free, and according to plan.

Soviet TNRD RD-0410 is the only working and reliable industrial nuclear rocket engine in the world

Currently, such work at the site has been stopped, although the equipment is maintained in relatively working condition. The test bench base of NPO Luch is the only experimental complex in the world where it is possible to test elements of nuclear propulsion reactors without significant financial and time costs. It is possible that the resumption in the United States of work on nuclear propulsion engines for flights to the Moon and Mars within the framework of the Space Research Initiative program with the planned participation of specialists from Russia and Kazakhstan will lead to the resumption of activity at the Semipalatinsk base and the implementation of a “Martian” expedition in the 2020s .

Main characteristics

Specific impulse on hydrogen: 910 - 980 sec(theoretically up to 1000 sec).

· Outflow velocity of the working fluid (hydrogen): 9100 - 9800 m/sec.

· Achievable thrust: up to hundreds and thousands of tons.

· Maximum operating temperatures: 3000°С - 3700°С (short-term switching on).

· Operating life: up to several thousand hours (periodic activation). /5/

11.Device

The design of the Soviet solid-phase nuclear rocket engine RD-0410

1 - line from the working fluid tank

2 - turbopump unit

3 - control drum drive

4 - radiation protection

5 - regulating drum

6 - retarder

7 - fuel assembly

8 - reactor vessel

9 - fire bottom

10 - nozzle cooling line

11- nozzle chamber

12 - nozzle

12.Operating principle

According to its operating principle, a TURE is a high-temperature reactor-heat exchanger into which a working fluid (liquid hydrogen) is introduced under pressure, and as it is heated to high temperatures (over 3000°C) it is ejected through a cooled nozzle. Heat regeneration in the nozzle is very beneficial, as it allows hydrogen to be heated much faster and, by utilizing a significant amount of thermal energy, the specific impulse can be increased to 1000 sec (9100-9800 m/s).

Nuclear rocket engine reactor

MsoNormalTable">

Working fluid

Density, g/cm3

Specific thrust (at specified temperatures in the heating chamber, °K), sec

0.071 (liquid)

0.682 (liquid)

1,000 (liquid)

No. Dann

No. Dann

No. Dann

(Note: The pressure in the heating chamber is 45.7 atm, expansion to a pressure of 1 atm with the same chemical composition of the working fluid) /6/

15.Benefits

The main advantage of TNREs over chemical rocket engines is the achievement of a higher specific impulse, significant energy reserves, compactness of the system and the ability to obtain very high thrust (tens, hundreds and thousands of tons in a vacuum. In general, the specific impulse achieved in a vacuum is greater than that of spent two-component chemical rocket fuel (kerosene-oxygen, hydrogen-oxygen) by 3-4 times, and when operating at the highest thermal intensity by 4-5 times.Currently in the USA and Russia there is significant experience in the development and construction of such engines, and if necessary (special programs space exploration) such engines can be produced in a short time and will have a reasonable cost.In the case of using TURE to accelerate spacecraft in space, and subject to the additional use of perturbation maneuvers using the gravitational field of large planets (Jupiter, Uranus, Saturn, Neptune) the achievable boundaries of studying the solar system are significantly expanding, and the time required to reach distant planets is significantly reduced. In addition, TNREs can be successfully used for devices operating in low orbits of giant planets using their rarefied atmosphere as a working fluid, or for operating in their atmosphere. /8/

16.Disadvantages

The main disadvantage of TNRE is the presence of a powerful flow of penetrating radiation (gamma radiation, neutrons), as well as the removal of highly radioactive uranium compounds, refractory compounds with induced radiation, and radioactive gases with the working fluid. In this regard, TURE is unacceptable for ground launches in order to avoid deterioration of the environmental situation at the launch site and in the atmosphere. /14/

17.Improving the characteristics of TURD. Hybrid turboprop engines

Like any rocket or any engine in general, a solid-phase nuclear jet engine has significant limitations on the most important characteristics achievable. These restrictions represent the inability of the device (TJRE) to operate in the temperature range exceeding the range of maximum operating temperatures of the engine’s structural materials. To expand the capabilities and significantly increase the main operating parameters of the TNRE, various hybrid schemes can be used in which the TNRE plays the role of a source of heat and energy and additional physical methods of accelerating the working fluids are used. The most reliable, practically feasible, and having high specific impulse and thrust characteristics is a hybrid scheme with an additional MHD circuit (magnetohydrodynamic circuit) for accelerating the ionized working fluid (hydrogen and special additives). /13/

18. Radiation hazard from nuclear propulsion engines.

A working nuclear engine is a powerful source of radiation - gamma and neutron radiation. Without taking special measures, radiation can cause unacceptable heating of the working fluid and structure in a spacecraft, embrittlement of metal structural materials, destruction of plastic and aging of rubber parts, damage to the insulation of electrical cables, and failure of electronic equipment. Radiation can cause induced (artificial) radioactivity of materials - their activation.

At present, the problem of radiation protection of spacecraft with nuclear propulsion engines is considered to be solved in principle. Fundamental issues related to the maintenance of nuclear propulsion engines at test stands and launch sites have also been resolved. Although an operating NRE poses a danger to operating personnel, already one day after the end of operation of the NRE, one can, without any personal protective equipment, stand for several tens of minutes at a distance of 50 m from the NRE and even approach it. The simplest means of protection allow operating personnel to enter the work area YARD shortly after the tests.

The level of contamination of launch complexes and the environment will apparently not be an obstacle to the use of nuclear propulsion engines on the lower stages of space rockets. The problem of radiation hazard for the environment and operating personnel is largely mitigated by the fact that hydrogen, used as a working fluid, is practically not activated when passing through the reactor. Therefore, the jet stream of a nuclear-powered engine is no more dangerous than the jet of a liquid-propellant rocket engine./4/

Conclusion

When considering the prospects for the development and use of nuclear propulsion engines in astronautics, one should proceed from the achieved and expected characteristics of various types of nuclear propulsion engines, from what their application can give to astronautics, and, finally, from the close connection of the problem of nuclear propulsion engines with the problem of energy supply in space and with issues of energy development at all.

As mentioned above, of all possible types of nuclear propulsion engines, the most developed are the thermal radioisotope engine and the engine with a solid-phase fission reactor. But if the characteristics of radioisotope nuclear propulsion engines do not allow us to hope for their widespread use in astronautics (at least in the near future), then the creation of solid-phase nuclear propulsion engines opens up great prospects for astronautics.

For example, a device has been proposed with an initial mass of 40,000 tons (i.e., approximately 10 times greater than that of the largest modern launch vehicles), with 1/10 of this mass accounting for the payload, and 2/3 for nuclear charges . If you detonate one charge every 3 seconds, then their supply will be enough for 10 days of continuous operation of the nuclear propulsion system. During this time, the device will accelerate to a speed of 10,000 km/s and in the future, after 130 years, it can reach the star Alpha Centauri.

Nuclear power plants have unique characteristics, which include virtually unlimited energy intensity, independence of operation from the environment, and immunity to external influences (cosmic radiation, meteorite damage, high and low temperatures, etc.). However, the maximum power of nuclear radioisotope installations is limited to a value of the order of several hundred watts. This limitation does not exist for nuclear reactor power plants, which determines the profitability of their use during long-term flights of heavy spacecraft in near-Earth space, during flights to the distant planets of the solar system and in other cases.

The advantages of solid-phase and other nuclear propulsion engines with fission reactors are most fully revealed in the study of such complex space programs as manned flights to the planets of the Solar System (for example, during an expedition to Mars). In this case, an increase in the specific impulse of the thruster makes it possible to solve qualitatively new problems. All these problems are greatly alleviated when using a solid-phase nuclear-propellant rocket engine with a specific impulse twice as high as that of modern liquid-propellant rocket engines. In this case, it also becomes possible to significantly reduce flight times.

It is most likely that in the near future solid-phase nuclear propulsion engines will become one of the most common rocket engines. Solid-phase nuclear propulsion engines can be used as devices for long-distance flights, for example, to such planets as Neptune, Pluto, and even to fly beyond the Solar System. However, for flights to the stars, a nuclear powered engine based on fission principles is not suitable. In this case, promising are nuclear engines or, more precisely, thermonuclear jet engines (TREs), operating on the principle of fusion reactions, and photonic jet engines (PREs), the source of momentum in which is the annihilation reaction of matter and antimatter. However, most likely humanity will use a different method of transportation to travel in interstellar space, different from jet.

In conclusion, I will give a paraphrase of Einstein’s famous phrase - to travel to the stars, humanity must come up with something that would be comparable in complexity and perception to a nuclear reactor for a Neanderthal!

LITERATURE

Sources:

1. "Rockets and People. Book 4 Moon Race" - M: Znanie, 1999.
2. http://www. lpre. de/energomash/index. htm
3. Pervushin “Battle for the Stars. Cosmic Confrontation” - M: knowledge, 1998.
4. L. Gilberg “Conquest of the sky” - M: Znanie, 1994.
5. http://epizodsspace. *****/bibl/molodtsov
6. “Engine”, “Nuclear engines for spacecraft”, No. 5 1999

7. "Engine", "Gas-phase nuclear engines for spacecraft",

No. 6, 1999
7. http://www. *****/content/numbers/263/03.shtml
8. http://www. lpre. de/energomash/index. htm
9. http://www. *****/content/numbers/219/37.shtml
10., Chekalin transport of the future.

M.: Knowledge, 1983.

11. , Chekalin space exploration. - M.:

Knowledge, 1988.

12. “Energy - Buran” - a step into the future // Science and life.-

13. Space technology. - M.: Mir, 1986.

14., Sergeyuk and commerce. - M.: APN, 1989.

15.USSR in space. 2005 - M.: APN, 1989.

16. On the way to deep space // Energy. - 1985. - No. 6.

APPLICATION

Main characteristics of solid-phase nuclear jet engines

Manufacturer country	Engine	Thrust in vacuum, kN	Specific impulse, sec		Project work, year
	NERVA/Lox Mixed Cycle

The Russian military has successfully tested a nuclear-powered cruise missile. Its flight range at subsonic speed is not limited. Such products are capable of bypassing air and missile defense areas at low altitude, destroying enemy targets with high precision. Russian President Vladimir Putin announced the appearance of the new product in his message to the Federal Assembly. According to experts, these systems are weapons of deterrence. They use air heated by a nuclear power plant to move.

According to experts, we are talking about a product with the index 9M730, developed by the Novator Design Bureau. During a period of threat, such missiles can be lifted into the air and deployed to specified areas. From there they will be able to strike important enemy targets. Testing of the new product is quite active, and the Il-976 flying laboratories are taking part in them.

At the end of 2017, the latest Russian cruise missile with a nuclear power plant was successfully launched at the Central Test Site of the Russian Federation. During the flight, the power plant reached the specified power and provided the required level of thrust,” Vladimir Putin said in his speech. - Russia's promising weapons systems are based on the latest unique achievements of our scientists, designers, and engineers. One of them is the creation of a small-sized, super-powerful nuclear power plant, which is placed in the body of a cruise missile such as our newest air-launched X-101 missile or the American Tomahawk, but at the same time provides tens of times - tens of times! - long flight range, which is practically unlimited. A low-flying, stealthy cruise missile carrying a nuclear warhead, with a virtually unlimited range, unpredictable flight path and the ability to bypass interception lines, is invulnerable to all existing and future missile defense and air defense systems.

In the presented video, viewers were able to see the launch of a unique rocket. The flight of the product was captured from an escort fighter. According to the computer graphics presented below, the “nuclear missile” flew around the naval missile defense zones in the Atlantic, went around South America from the south and hit the United States from the Pacific Ocean.

Judging by the video presented, this is either a sea- or land-based missile,” Dmitry Kornev, editor-in-chief of the MilitaryRussia project, told Izvestia. - There are two developers of cruise missiles in Russia. Raduga produces only air-launched products. Land and sea are under the jurisdiction of Novator. This company has a line of R-500 cruise missiles for the Iskander complexes, as well as the legendary Caliber missiles.

Not long ago, references to two new products appeared in open documents of the Novator Design Bureau - 9M729 and 9M730. The first is an ordinary long-range cruise missile, but nothing was known about the 9M730. But this product is clearly under active development - several tenders have been posted on this topic on the government procurement website. Therefore, we can assume that the “nuclear missile” is the 9M730.

As military historian Dmitry Boltenkov noted, the operating principle of a nuclear power plant is quite simple.

On the sides of the rocket there are special compartments with powerful and compact heaters powered by a nuclear power plant, the expert noted. - Atmospheric air enters them, which heats up to several thousand degrees and turns into the working fluid of the engine. The flow of hot air creates draft. Such a system truly provides an almost unlimited flight range.

As Vladimir Putin stated, the new product was tested at the Central Test Site. This facility is located in the Arkhangelsk region in the village of Nenoksa.

This is a historical place for testing long-range weapons,” noted Dmitry Boltenkov. - From there, the missile routes run along the northern coast of Russia. Their length can reach up to several thousand kilometers. To take telemetry parameters from missiles at such distances, special aircraft are needed - flying laboratories.

According to the expert, two unique Il-976 aircraft were recently restored. These are special vehicles, created on the basis of the transport Il-76, which have been used for a long time to test long-range missile weapons. In the 1990s they were mothballed.

Photos of Il-976 flying to an airfield near Arkhangelsk were published on the Internet, the expert noted. - It is noteworthy that the cars bore the Rosatom emblem. At the same time, Russia issued a special international warning NOTAM (Notice to Airmen) and closed the area to ships and aircraft.

According to military expert Vladislav Shurygin, the new “nuclear missile” is not an offensive combat system, but a deterrent weapon.

In a threatened period (an aggravation of the situation, as a rule, preceding the outbreak of war), the Russian military will be able to withdraw these products to specified patrol areas, the expert noted. - This will prevent enemy attempts to strike Russia and its allies. “Nuclear” missiles will be able to serve as retaliatory weapons or launch a preemptive strike.

The Russian Armed Forces have several lines of subsonic low-altitude cruise missiles. These are the Kh-555 and Kh-101 airborne, the P-500 ground-based and the 3M14 "Caliber" sea-based.