Nuclear fuel rocket engine. Nuclear space engine

Found an interesting article. In general, nuclear spaceships have always interested me. This is the future of astronautics. Extensive work on this topic was also carried out in the USSR. The article is just about them.

To space on nuclear power. Dreams and reality.

Doctor of Physical and Mathematical Sciences Yu. Ya. Stavissky

In 1950, I defended my diploma as an engineer-physicist at the Moscow Mechanical Institute (MMI) of the Ministry of Ammunition. Five years earlier, in 1945, the Faculty of Engineering and Physics was formed there, training specialists for the new industry, whose tasks mainly included the production of nuclear weapons. The faculty was second to none. Along with fundamental physics in the scope of university courses (methods of mathematical physics, theory of relativity, quantum mechanics, electrodynamics, statistical physics and others), we were taught a full range of engineering disciplines: chemistry, metallurgy, strength of materials, theory of mechanisms and machines, etc. Created by an outstanding Soviet physicist Alexander Ilyich Leypunsky, the Faculty of Engineering and Physics of MMI grew over time into the Moscow Engineering and Physics Institute (MEPhI). Another engineering and physics faculty, which also later merged with MEPhI, was formed at the Moscow Power Engineering Institute (MPEI), but if at MMI the main emphasis was on fundamental physics, then at the Energetic Institute it was on thermal and electrical physics.

We studied quantum mechanics from the book of Dmitry Ivanovich Blokhintsev. Imagine my surprise when, upon assignment, I was sent to work with him. I, an avid experimenter (as a child, I took apart all the clocks in the house), and suddenly I find myself with a famous theorist. I was seized with a slight panic, but upon arrival at the place - “Object B” of the USSR Ministry of Internal Affairs in Obninsk - I immediately realized that I was worrying in vain.

By this time, the main topic of “Object B”, which until June 1950 was actually headed by A.I. Leypunsky, has already formed. Here they created reactors with expanded reproduction of nuclear fuel - “fast breeders”. As director, Blokhintsev initiated the development of a new direction - the creation of nuclear-powered engines for space flights. Mastering space was a long-time dream of Dmitry Ivanovich; even in his youth he corresponded and met with K.E. Tsiolkovsky. I think that understanding the gigantic possibilities of nuclear energy, according to calorific value millions of times higher than the best chemical fuels, and determined life path DI. Blokhintseva.
“You can’t see face to face”... In those years we didn’t understand much. Only now, when the opportunity has finally arisen to compare the deeds and destinies of the outstanding scientists of the Physics and Energy Institute (PEI) - the former “Object B”, renamed on December 31, 1966 - is a correct, as it seems to me, understanding of the ideas that motivated them at that time emerging . With all the variety of activities that the institute had to deal with, it is possible to identify priority scientific areas that were in the sphere of interests of its leading physicists.

The main interest of AIL (as Alexander Ilyich Leypunsky was called behind his back at the institute) is the development of global energy based on fast breeder reactors (nuclear reactors that have no restrictions on nuclear fuel resources). It is difficult to overestimate the importance of this truly “cosmic” problem, to which he devoted the last quarter century of his life. Leypunsky spent a lot of energy on the defense of the country, in particular on the creation of nuclear engines for submarines and heavy aircraft.

Interests D.I. Blokhintsev (he got the nickname “D.I.”) were aimed at solving the problem of using nuclear energy for space flights. Unfortunately, at the end of the 1950s, he was forced to leave this work and lead the creation of an international scientific center - the Joint Institute for Nuclear Research in Dubna. There he worked on pulsed fast reactors - IBR. This became the last big thing of his life.

One goal - one team

DI. Blokhintsev, who taught at Moscow State University in the late 1940s, noticed there and then invited the young physicist Igor Bondarenko, who was literally raving about nuclear-powered spaceships, to work in Obninsk. His first scientific supervisor was A.I. Leypunsky, and Igor, naturally, dealt with his topic - fast breeders.

Under D.I. Blokhintsev, a group of scientists formed around Bondarenko, who united to solve the problems of using atomic energy in space. In addition to Igor Ilyich Bondarenko, the group included: Viktor Yakovlevich Pupko, Edwin Aleksandrovich Stumbur and the author of these lines. The main ideologist was Igor. Edwin conducted experimental studies of ground-based models of nuclear reactors in space installations. I worked mainly on “low thrust” rocket engines (thrust in them is created by a kind of accelerator - “ion propulsion”, which is powered by energy from a space nuclear power plant). We investigated the processes
flowing in ion propulsors, on ground stands.

On Viktor Pupko (in the future
he became the head of the space technology department of the IPPE) there was a lot of organizational work. Igor Ilyich Bondarenko was an outstanding physicist. He had a keen sense of experimentation and carried out simple, elegant and very effective experiments. I think that no experimentalist, and perhaps few theorists, “felt” fundamental physics. Always responsive, open and friendly, Igor was truly the soul of the institute. To this day, the IPPE lives by his ideas. Bondarenko lived unjustifiably short life. In 1964, at the age of 38, he died tragically due to medical error. It was as if God, seeing how much man had done, decided that it was too much and commanded: “Enough.”

One cannot help but recall another unique personality - Vladimir Aleksandrovich Malykh, a technologist “from God,” a modern Leskovsky Lefty. If the “products” of the above-mentioned scientists were mainly ideas and calculated estimates of their reality, then Malykh’s works always had an output “in metal”. Its technology sector, which at the time of the IPPE's heyday numbered more than two thousand employees, could do, without exaggeration, anything. Moreover, he himself always played the key role.

V.A. Malykh began as a laboratory assistant at the Research Institute of Nuclear Physics of Moscow State University, having completed three courses in physics; the war did not allow him to complete his studies. At the end of the 1940s, he managed to create a technology for the production of technical ceramics based on beryllium oxide, a unique dielectric material with high thermal conductivity. Before Malykh, many struggled unsuccessfully with this problem. A fuel cell based on serial of stainless steel and natural uranium, which he developed for the first nuclear power plant, is a miracle in those times and even today. Or the thermionic fuel element of the reactor-electric generator created by Malykh to power spacecraft - “garland”. Until now, nothing better has appeared in this area. Malykh’s creations were not demonstration toys, but elements of nuclear technology. They worked for months and years. Vladimir Aleksandrovich became a Doctor of Technical Sciences, laureate of the Lenin Prize, Hero of Socialist Labor. In 1964, he tragically died from the consequences of military shell shock.

Step by step

S.P. Korolev and D.I. Blokhintsev has long nurtured the dream of manned space flight. Close working ties were established between them. But in the early 1950s, at the height of the cold war“, no expense was spared only for military purposes. Rocketry was considered only as a carrier of nuclear charges, and they did not even think about satellites. Meanwhile, Bondarenko, knowing about the latest achievements of rocket scientists, persistently advocated the creation of an artificial Earth satellite. Subsequently, no one remembered this.

The history of the creation of the rocket that lifted the planet’s first cosmonaut, Yuri Gagarin, into space is interesting. It is connected with the name of Andrei Dmitrievich Sakharov. At the end of the 1940s, he developed a combined fission-thermonuclear charge - “sloyka”, apparently independently of “father hydrogen bomb“Edward Teller, who proposed a similar product called “alarm clock”. However, Teller soon realized that a nuclear charge of such a design would have a “limited” power, no more than ~ 500 kilotons of ton equivalent. This is not enough for an “absolute” weapon, so the “alarm clock” was abandoned. In the Union, in 1953, Sakharov’s RDS-6s puff paste was blown up.

After successful tests and Sakharov’s election as an academician, the then head of the Ministry of Medium Machine Building V.A. Malyshev invited him to his place and set him the task of determining the parameters of the next generation bomb. Andrei Dmitrievich estimated (without detailed study) the weight of the new, much more powerful charge. Sakharov’s report formed the basis for a resolution of the CPSU Central Committee and the USSR Council of Ministers, which obliged S.P. Korolev to develop a ballistic launch vehicle for this charge. It was precisely this R-7 rocket called “Vostok” that launched an artificial Earth satellite into orbit in 1957 and a spacecraft with Yuri Gagarin in 1961. It was no longer planned to use it as a carrier of a heavy nuclear charge, since the development thermonuclear weapons went a different way.

At the initial stage of the space nuclear program, IPPE, together with Design Bureau V.N. Chelomeya was developing a nuclear cruise missile. This direction did not develop for long and ended with calculations and testing of engine elements created in the department of V.A. Malykha. In essence, we were talking about a low-flying unmanned aircraft with a ramjet nuclear engine and a nuclear warhead (a kind of nuclear analogue of the “buzzing bug” - the German V-1). The system was launched using conventional rocket boosters. After reaching the given speed, thrust was created atmospheric air, heated by the fission chain reaction of beryllium oxide impregnated with enriched uranium.

Generally speaking, the ability of a rocket to perform a particular astronautics task is determined by the speed it acquires after using up the entire supply of working fluid (fuel and oxidizer). It is calculated using the Tsiolkovsky formula: V = c×lnMn/ Mk, where c is the exhaust velocity of the working fluid, and Mn and Mk are the initial and final mass of the rocket. In conventional chemical rockets, the exhaust velocity is determined by the temperature in the combustion chamber, the type of fuel and oxidizer, and the molecular weight of the combustion products. For example, the Americans used hydrogen as fuel in the descent module to land astronauts on the Moon. The product of its combustion is water, whose molecular weight is relatively low, and the flow rate is 1.3 times higher than when burning kerosene. This is enough for the descent vehicle with astronauts to reach the surface of the Moon and then return them to the orbit of its artificial satellite. Korolev’s work with hydrogen fuel was suspended due to an accident with human casualties. We did not have time to create a lunar lander for humans.

One of the ways to significantly increase the exhaust rate is to create nuclear thermal rockets. For us, these were ballistic nuclear missiles (BAR) with a range of several thousand kilometers (a joint project of OKB-1 and IPPE), while for the Americans, similar systems of the “Kiwi” type were used. The engines were tested at testing sites near Semipalatinsk and Nevada. The principle of their operation is as follows: hydrogen is heated in a nuclear reactor to high temperatures, passes into the atomic state and in this form flows out of the rocket. In this case, the exhaust speed increases by more than four times compared to a chemical hydrogen rocket. The question was to find out to what temperature hydrogen could be heated in a reactor with solid fuel cells. Calculations gave about 3000°K.

At NII-1, whose scientific director was Mstislav Vsevolodovich Keldysh (then President of the USSR Academy of Sciences), the department of V.M. Ievleva, with the participation of the IPPE, was working on a completely fantastic scheme - a gas-phase reactor in which a chain reaction occurs in a gas mixture of uranium and hydrogen. Hydrogen flows out of such a reactor ten times faster than from a solid fuel reactor, while uranium is separated and remains in the core. One of the ideas involved the use of centrifugal separation, when a hot gas mixture of uranium and hydrogen is “swirled” by incoming cold hydrogen, as a result of which the uranium and hydrogen are separated, as in a centrifuge. Ievlev tried, in fact, to directly reproduce the processes in the combustion chamber of a chemical rocket, using as an energy source not the heat of fuel combustion, but the fission chain reaction. This opened the way to the full use of the energy capacity of atomic nuclei. But the question of the possibility of pure hydrogen (without uranium) flowing out of the reactor remained unresolved, not to mention the technical problems associated with containing high-temperature gas mixtures at pressures of hundreds of atmospheres.

IPPE's work on ballistic nuclear missiles ended in 1969-1970 with “fire tests” at the Semipalatinsk test site of a prototype nuclear rocket engine with solid fuel elements. It was created by the IPPE in cooperation with the Voronezh Design Bureau A.D. Konopatov, Moscow Research Institute-1 and a number of other technological groups. The basis of the engine with a thrust of 3.6 tons was the IR-100 nuclear reactor with fuel elements made of a solid solution of uranium carbide and zirconium carbide. The hydrogen temperature reached 3000°K with a reactor power of ~170 MW.

Low thrust nuclear rockets

So far we have been talking about rockets with a thrust exceeding their weight, which could be launched from the surface of the Earth. In such systems, increasing the exhaust velocity makes it possible to reduce the supply of working fluid, increase the payload, and eliminate multi-stage operation. However, there are ways to achieve practically unlimited exhaust velocities, for example, acceleration of matter electromagnetic fields. I worked in this area in close contact with Igor Bondarenko for almost 15 years.

The acceleration of a rocket with an electric propulsion engine (EPE) is determined by the ratio of the specific power of the space nuclear power plant (SNPP) installed on them to the exhaust velocity. In the foreseeable future, the specific power of the KNPP, apparently, will not exceed 1 kW/kg. In this case, it is possible to create rockets with low thrust, tens and hundreds of times less than the weight of the rocket, and with very low consumption of the working fluid. Such a rocket can only launch from the orbit of an artificial Earth satellite and, slowly accelerating, reach high speeds.

For flights within solar system We need rockets with an exhaust speed of 50-500 km/s, and for flights to the stars we need “photon rockets” that go beyond our imagination with an exhaust speed equal to the speed of light. In order to carry out a long-distance space flight of any reasonable time, unimaginable power density of power plants is required. It is not yet possible to even imagine what physical processes they could be based on.

Calculations have shown that during the Great Confrontation, when the Earth and Mars are closest to each other, it is possible to fly a nuclear spacecraft with a crew to Mars in one year and return it to the orbit of an artificial Earth satellite. The total weight of such a ship is about 5 tons (including the supply of the working fluid - cesium, equal to 1.6 tons). It is determined mainly by the mass of the KNPP with a power of 5 MW, and the jet thrust is determined by a two-megawatt beam of cesium ions with an energy of 7 kiloelectronvolts *. The ship launches from the orbit of an artificial Earth satellite, enters the orbit of a Mars satellite, and will have to descend to its surface on a device with a hydrogen chemical engine, similar to the American lunar one.

This direction, based on technical solutions possible today, a large series of works was devoted to IPPE.

Ion propulsion

In those years, ways of creating various electric propulsion systems for spacecraft, such as “plasma guns”, electrostatic accelerators of “dust” or liquid droplets were discussed. However, none of the ideas had a clear basis. physical basis. The discovery was surface ionization of cesium.

Back in the 20s of the last century, American physicist Irving Langmuir discovered the surface ionization of alkali metals. When a cesium atom evaporates from the surface of a metal (in our case, tungsten), whose electron work function is greater than the cesium ionization potential, in almost 100% of cases it loses a weakly bound electron and turns out to be a singly charged ion. Thus, the surface ionization of cesium on tungsten is the physical process that makes it possible to create an ion propulsion device with almost 100% utilization of the working fluid and with an energy efficiency close to unity.

Our colleague Stal Yakovlevich Lebedev played a major role in creating models of an ion propulsion system of this type. With his iron tenacity and perseverance, he overcame all obstacles. As a result, it was possible to reproduce a flat three-electrode ion propulsion circuit in metal. The first electrode is a tungsten plate measuring approximately 10x10 cm with a potential of +7 kV, the second is a tungsten grid with a potential of -3 kV, and the third is a thoriated tungsten grid with zero potential. The “molecular gun” produced a beam of cesium vapor, which, through all the grids, fell on the surface of the tungsten plate. A balanced and calibrated metal plate, the so-called balance, served to measure the “force,” i.e., the thrust of the ion beam.

The accelerating voltage to the first grid accelerates cesium ions to 10,000 eV, the decelerating voltage to the second grid slows them down to 7000 eV. This is the energy with which the ions must leave the thruster, which corresponds to an exhaust speed of 100 km/s. But a beam of ions, limited by the space charge, cannot “go into outer space.” The volumetric charge of the ions must be compensated by electrons in order to form a quasi-neutral plasma, which spreads unhindered in space and creates reactive thrust. The source of electrons to compensate for the volume charge of the ion beam is the third grid (cathode) heated by current. The second, “blocking” grid prevents electrons from getting from the cathode to the tungsten plate.

The first experience with the ion propulsion model marked the beginning of more than ten years of work. One of the latest models, with a porous tungsten emitter, created in 1965, produced a “thrust” of about 20 g at an ion beam current of 20 A, had an energy utilization rate of about 90% and a matter utilization rate of 95%.

Direct conversion of nuclear heat into electricity

Ways to directly convert nuclear fission energy into electrical energy have not yet been found. We still cannot do without an intermediate link - a heat engine. Since its efficiency is always less than one, the “waste” heat needs to be put somewhere. There are no problems with this on land, in water or in the air. In space, there is only one way - thermal radiation. Thus, KNPP cannot do without a “refrigerator-emitter”. The radiation density is proportional to the fourth power absolute temperature, therefore the temperature of the radiator refrigerator should be as high as possible. Then it will be possible to reduce the area of ​​the radiating surface and, accordingly, the mass of the power plant. We came up with the idea of ​​using “direct” conversion of nuclear heat into electricity, without a turbine or generator, which seemed more reliable for long-term operation at high temperatures.

From the literature we knew about the works of A.F. Ioffe - the founder of the Soviet school of technical physics, a pioneer in the research of semiconductors in the USSR. Few people now remember the current sources he developed, which were used during the Great Patriotic War. At that time, more than one partisan detachment had contact with the mainland thanks to “kerosene” TEGs - Ioffe thermoelectric generators. A “crown” made of TEGs (it was a set of semiconductor elements) was put on a kerosene lamp, and its wires were connected to radio equipment. The “hot” ends of the elements were heated by the flame of a kerosene lamp, the “cold” ends were cooled in air. The heat flow, passing through the semiconductor, generated an electromotive force, which was enough for a communication session, and in the intervals between them the TEG charged the battery. When, ten years after the Victory, we visited the Moscow TEG plant, it turned out that they were still being sold. Many villagers then had economical Rodina radios with direct-heat lamps, powered by a battery. TAGs were often used instead.

The problem with kerosene TEG is its low efficiency (only about 3.5%) and low maximum temperature (350°K). But the simplicity and reliability of these devices attracted developers. Thus, semiconductor converters developed by the group of I.G. Gverdtsiteli at the Sukhumi Institute of Physics and Technology, found application in space installations of the Buk type.

At one time A.F. Ioffe proposed another thermionic converter - a diode in a vacuum. The principle of its operation is as follows: the heated cathode emits electrons, some of them, overcoming the potential of the anode, do work. Much higher efficiency (20-25%) was expected from this device at operating temperatures above 1000°K. In addition, unlike a semiconductor, a vacuum diode is not afraid of neutron radiation, and it can be combined with a nuclear reactor. However, it turned out that it was impossible to implement the idea of ​​Ioffe’s “vacuum” converter. As in an ion propulsion device, in a vacuum converter you need to get rid of the space charge, but this time not ions, but electrons. A.F. Ioffe intended to use micron gaps between the cathode and anode in a vacuum converter, which is practically impossible under conditions of high temperatures and thermal deformations. This is where cesium comes in handy: one cesium ion produced by surface ionization at the cathode compensates for the space charge of about 500 electrons! In essence, a cesium converter is a “reversed” ion propulsion device. Physical processes they are close.

“Garlands” by V.A. Malykha

One of the results of IPPE's work on thermionic converters was the creation of V.A. Malykh and serial production in his department of fuel elements from series-connected thermionic converters - “garlands” for the Topaz reactor. They provided up to 30 V - a hundred times more than single-element converters created by “competing organizations” - the Leningrad group M.B. Barabash and later - the Institute of Atomic Energy. This made it possible to “remove” from the reactor tens and hundreds of times more power. However, the reliability of the system, stuffed with thousands of thermionic elements, raised concerns. At the same time, steam and gas turbine plants operated without failures, so we also paid attention to the “machine” conversion of nuclear heat into electricity.

The whole difficulty lay in the resource, because in long-distance space flights, turbogenerators must operate for a year, two, or even several years. To reduce wear, the “revolutions” (turbine rotation speed) should be made as low as possible. On the other hand, a turbine operates efficiently if the speed of the gas or steam molecules is close to the speed of its blades. Therefore, first we considered the use of the heaviest - mercury steam. But we were frightened by the intense radiation-stimulated corrosion of iron and stainless steel that occurred in a mercury-cooled nuclear reactor. In two weeks, corrosion “ate” the fuel elements of the experimental fast reactor “Clementine” at the Argonne Laboratory (USA, 1949) and the BR-2 reactor at the IPPE (USSR, Obninsk, 1956).

Potassium vapor turned out to be tempting. The reactor with potassium boiling in it formed the basis of the power plant we were developing for a low-thrust spacecraft - potassium steam rotated the turbogenerator. This “machine” method of converting heat into electricity made it possible to count on an efficiency of up to 40%, while real thermionic installations provided an efficiency of only about 7%. However, KNPP with “machine” conversion of nuclear heat into electricity was not developed. The matter ended with the release of a detailed report, essentially a “physical note” to technical project low-thrust spacecraft for a crewed flight to Mars. The project itself was never developed.

Later, I think, interest in space flights using nuclear rocket engines simply disappeared. After the death of Sergei Pavlovich Korolev, support for IPPE’s work on ion propulsion and “machine” nuclear power plants noticeably weakened. OKB-1 was headed by Valentin Petrovich Glushko, who had no interest in bold, promising projects. The Energia Design Bureau, which he created, built powerful chemical rockets and the Buran spacecraft returning to Earth.

"Buk" and "Topaz" on the satellites of the "Cosmos" series

Work on the creation of KNPP with direct conversion of heat into electricity, now as power sources for powerful radio satellites (space radar stations and television broadcasters), continued until the start of perestroika. From 1970 to 1988, about 30 radar satellites were launched into space with Buk nuclear power plants with semiconductor converter reactors and two with Topaz thermionic plants. The Buk, in fact, was a TEG - a semiconductor Ioffe converter, but instead of a kerosene lamp it used a nuclear reactor. It was a fast reactor with a power of up to 100 kW. The full load of highly enriched uranium was about 30 kg. Heat from the core was transferred by liquid metal - a eutectic alloy of sodium and potassium - to semiconductor batteries. Electric power reached 5 kW.

The Buk installation, under the scientific guidance of the IPPE, was developed by OKB-670 specialists M.M. Bondaryuk, later - NPO "Red Star" (chief designer - G.M. Gryaznov). The Dnepropetrovsk Yuzhmash Design Bureau (chief designer - M.K. Yangel) was tasked with creating a launch vehicle to launch the satellite into orbit.

The operating time of “Buk” is 1-3 months. If the installation failed, the satellite was transferred to a long-term orbit at an altitude of 1000 km. Over almost 20 years of launches, there were three cases of a satellite falling to Earth: two in the ocean and one on land, in Canada, in the vicinity of Great Slave Lake. Kosmos-954, launched on January 24, 1978, fell there. He worked for 3.5 months. The satellite's uranium elements burned completely in the atmosphere. Only the remains of a beryllium reflector and semiconductor batteries were found on the ground. (All this data is presented in the joint report of the US and Canadian atomic commissions on Operation Morning Light.)

The Topaz thermionic nuclear power plant used a thermal reactor with a power of up to 150 kW. The full load of uranium was about 12 kg - significantly less than that of the Buk. The basis of the reactor were fuel elements - “garlands”, developed and manufactured by Malykh’s group. They consisted of a chain of thermoelements: the cathode was a “thimble” of tungsten or molybdenum filled with uranium oxide, the anode was a thin-walled tube of niobium cooled by liquid sodium-potassium. The cathode temperature reached 1650°C. The electrical power of the installation reached 10 kW.

The first flight model, the Cosmos-1818 satellite with the Topaz installation, entered orbit on February 2, 1987 and operated flawlessly for six months until cesium reserves were exhausted. The second satellite, Cosmos-1876, was launched a year later. He worked in orbit almost twice as long. The main developer of Topaz was the MMZ Soyuz Design Bureau, headed by S.K. Tumansky (former design bureau of aircraft engine designer A.A. Mikulin).

This was in the late 1950s, when we were working on ion propulsion, and he was working on the third stage engine for a rocket that would fly around the Moon and land on it. Memories of Melnikov’s laboratory are still fresh to this day. It was located in Podlipki (now the city of Korolev), on site No. 3 of OKB-1. A huge workshop with an area of ​​about 3000 m2, filled with dozens of desks with loopback oscilloscopes recording on 100 mm roll paper (this was still past era, today one personal computer would be enough). At the front wall of the workshop there is a stand where the combustion chamber of the “lunar” rocket engine is mounted. Oscilloscopes have thousands of wires from sensors for gas velocity, pressure, temperature and other parameters. The day begins at 9.00 with the ignition of the engine. It runs for several minutes, then immediately after stopping, a team of first-shift mechanics disassembles it, carefully inspects and measures the combustion chamber. At the same time, oscilloscope tapes are analyzed and recommendations for design changes are made. Second shift - designers and workshop workers make recommended changes. During the third shift, a new combustion chamber and diagnostic system are installed at the stand. A day later, at exactly 9.00 am, the next session. And so on without days off for weeks, months. More than 300 engine options per year!

This is how chemical rocket engines were created, which had to work for only 20-30 minutes. What can we say about testing and modifications of nuclear power plants - the calculation was that they should work for more than one year. This required truly gigantic efforts.

A safe method of using nuclear energy in space was invented in the USSR, and work is now underway to create a nuclear installation based on it, said the General Director of the State Scientific Center of the Russian Federation “Keldysh Research Center”, Academician Anatoly Koroteev.

“Now the institute is actively working in this direction in large cooperation between Roscosmos and Rosatom enterprises. And I hope that in due time we will get a positive effect here,” A. Koroteev said at the annual “Royal Readings” at the Bauman Moscow State Technical University on Tuesday.

According to him, the Keldysh Center has invented a scheme for the safe use of nuclear energy in outer space, which makes it possible to do without emissions and operates in a closed circuit, which makes the installation safe even if it fails and falls to Earth.

“This scheme greatly reduces the risk of using nuclear energy, especially considering that one of the fundamental points is the operation of this system in orbits above 800-1000 km. Then, in case of failure, the “flashing” time is such that it makes it safe for these elements to return to Earth after a long period of time,” the scientist clarified.

A. Koroteev said that previously the USSR had already used spacecraft powered by nuclear energy, but they were potentially dangerous for the Earth, and subsequently had to be abandoned. “The USSR used nuclear energy in space. There were 34 spacecraft with nuclear energy in space, of which 32 were Soviet and two American,” the academician recalled.

According to him, the nuclear installation being developed in Russia will be made lighter through the use of a frameless cooling system, in which the nuclear reactor coolant will circulate directly in outer space without a pipeline system.

But back in the early 1960s, designers considered nuclear rocket engines as the only real alternative for traveling to other planets in the solar system. Let's find out the history of this issue.

The competition between the USSR and the USA, including in space, was going on at that time full swing, engineers and scientists entered the race to create a nuclear propulsion engine, and the military also initially supported the nuclear rocket engine project. At first, the task seemed very simple - you just need to make a reactor designed to be cooled with hydrogen rather than water, attach a nozzle to it, and - forward to Mars! The Americans were going to Mars ten years after the Moon and could not even imagine that astronauts would ever reach it without nuclear engines.

The Americans very quickly built the first prototype reactor and already tested it in July 1959 (they were called KIWI-A). These tests merely showed that the reactor could be used to heat hydrogen. The reactor design - with unprotected uranium oxide fuel - was not suitable for high temperatures, and the hydrogen only heated up to one and a half thousand degrees.

As experience was gained, the design of reactors for nuclear rocket engines - NRE - became more complex. The uranium oxide was replaced with a more heat-resistant carbide, in addition it was coated with niobium carbide, but when trying to reach the design temperature, the reactor began to collapse. Moreover, even in the absence of macroscopic destruction, diffusion of uranium fuel into cooling hydrogen occurred, and mass loss reached 20% within five hours of reactor operation. A material capable of operating at 2700-3000 0 C and resisting destruction by hot hydrogen has never been found.

Therefore, the Americans decided to sacrifice efficiency and included specific impulse in the flight engine design (thrust in kilograms of force achieved with the release of one kilogram of working fluid mass every second; the unit of measurement is a second). 860 seconds. This was twice the corresponding figure for oxygen-hydrogen engines of that time. But when the Americans began to succeed, interest in manned flights had already fallen, the Apollo program was curtailed, and in 1973 the NERVA project (that was the name of the engine for a manned expedition to Mars) was finally closed. Having won the lunar race, the Americans did not want to organize a Martian race.

But the lesson learned from the dozens of reactors built and the dozens of tests conducted was that American engineers got too carried away with full-scale nuclear testing rather than working out key elements without involving nuclear technology where it could be avoided. And where it is not possible, use smaller stands. The Americans "drove" almost all reactors to full power, but were unable to reach the design temperature of hydrogen - the reactor began to collapse earlier. In total, from 1955 to 1972, $1.4 billion was spent on the nuclear rocket engine program - approximately 5% of the cost of the lunar program.

Also in the USA, the Orion project was invented, which combined both versions of the nuclear propulsion system (jet and pulse). This was done in the following way: small nuclear charges with a capacity of about 100 tons of TNT were ejected from the tail of the ship. Metal discs were fired after them. At a distance from the ship, the charge was detonated, the disk evaporated, and the substance scattered in different directions. Part of it fell into the reinforced tail section of the ship and moved it forward. A small increase in thrust should have been provided by the evaporation of the plate taking the blows. The unit cost of such a flight should have been only 150 then dollars per kilogram of payload.

It even got to the point of testing: experience showed that movement with the help of successive impulses is possible, as is the creation of a stern plate of sufficient strength. But the Orion project was closed in 1965 as unpromising. However, this is so far the only existing concept that can allow expeditions at least across the solar system.

In the first half of the 1960s, Soviet engineers viewed the expedition to Mars as a logical continuation of the then-developed program of manned flight to the Moon. In the wake of the excitement caused by the USSR's priority in space, even such extremely complex problems were assessed with increased optimism.

One of the most important problems was (and remains to this day) the problem of power supply. It was clear that liquid-propellant rocket engines, even promising oxygen-hydrogen ones, could, in principle, provide a manned flight to Mars, then only with huge launch masses of the interplanetary complex, with a large number of dockings of individual blocks in the assembly low-Earth orbit.

In search of optimal solutions, scientists and engineers turned to nuclear energy, gradually taking a closer look at this problem.

In the USSR, research on the problems of using nuclear energy in rocket and space technology began in the second half of the 50s, even before the launch of the first satellites. Small groups of enthusiasts emerged in several research institutes with the goal of creating rocket and space nuclear engines and power plants.

The designers of OKB-11 S.P. Korolev, together with specialists from NII-12 under the leadership of V.Ya. Likhushin, considered several options for space and combat (!) rockets equipped with nuclear rocket engines (NRE). Water and liquefied gases - hydrogen, ammonia and methane - were evaluated as the working fluid.

The prospect was promising; gradually the work found understanding and financial support in the USSR government.

Already the very first analysis showed that among the many possible schemes of space nuclear power propulsion systems (NPS), three have the greatest prospects:

• with a solid-phase nuclear reactor;
• with a gas-phase nuclear reactor;
• electronuclear rocket propulsion systems.

The schemes were fundamentally different; For each of them, several options were outlined for the development of theoretical and experimental work.

The closest to implementation seemed to be a solid-phase nuclear propulsion engine. The impetus for the development of work in this direction was provided by similar developments carried out in the USA since 1955 under the ROVER program, as well as the prospects (as it seemed then) of creating a domestic intercontinental manned bomber aircraft with a nuclear propulsion system.

A solid-phase nuclear propulsion engine operates as a direct-flow engine. Liquid hydrogen enters the nozzle part, cools the reactor vessel, fuel assemblies (FA), moderator, and then turns around and gets inside the FA, where it heats up to 3000 K and is thrown into the nozzle, accelerating to high speeds.

The operating principles of the nuclear engine were not in doubt. However, its design (and characteristics) largely depended on the “heart” of the engine – the nuclear reactor and were determined, first of all, by its “filling” – the core.

The developers of the first American (and Soviet) nuclear propulsion engines advocated a homogeneous reactor with a graphite core. The work of the search group on new types of high-temperature fuels, created in 1958 in laboratory No. 21 (headed by G.A. Meerson) of NII-93 (director A.A. Bochvar), proceeded somewhat separately. Influenced by the ongoing work on an aircraft reactor (a honeycomb of beryllium oxide) at that time, the group made attempts (again exploratory) to obtain materials based on silicon and zirconium carbide that were resistant to oxidation.

According to the memoirs of R.B. Kotelnikov, an employee of NII-9, in the spring of 1958, the head of laboratory No. 21 had a meeting with a representative of NII-1, V.N. Bogin. He said that as the main material for the fuel elements (fuel rods) of the reactor in their institute (by the way, at that time the head one in the rocket industry; head of the institute V.Ya. Likhushin, scientific director M.V. Keldysh, head of the laboratory V.M. .Ievlev) use graphite. In particular, they have already learned how to apply coatings to samples to protect them from hydrogen. NII-9 proposed to consider the possibility of using UC-ZrC carbides as the basis for fuel elements.

Later a short time Another customer for fuel rods appeared - the Design Bureau of M.M. Bondaryuk, which ideologically competed with NII-1. If the latter stood for a multi-channel all-block design, then the Design Bureau of M.M. Bondaryuk headed for a collapsible plate version, focusing on the ease of machining of graphite and not being embarrassed by the complexity of the parts - millimeter-thick plates with the same ribs. Carbides are much more difficult to process; at that time it was impossible to make parts such as multi-channel blocks and plates from them. It became clear that it was necessary to create some other design that would correspond to the specifics of carbides.

At the end of 1959 - beginning of 1960, the decisive condition for NRE fuel rods was found - a rod type core, satisfying the customers - the Likhushin Research Institute and the Bondaryuk Design Bureau. The design of a heterogeneous reactor on thermal neutrons was justified as the main one for them; its main advantages (compared to the alternative homogeneous graphite reactor) are:

• it is possible to use a low-temperature hydrogen-containing moderator, which makes it possible to create nuclear propulsion engines with high mass perfection;
• it is possible to develop a small-sized prototype of a nuclear propulsion engine with a thrust of about 30...50 kN s high degree continuity for engines and nuclear power plants of the next generation;
• it is possible to widely use refractory carbides in fuel rods and other parts of the reactor structure, which makes it possible to maximize the heating temperature of the working fluid and provide an increased specific impulse;
• it is possible to autonomously test, element by element, the main components and systems of the nuclear propulsion system (NPP), such as fuel assemblies, moderator, reflector, turbopump unit (TPU), control system, nozzle, etc.; this allows testing to be carried out in parallel, reducing the amount of expensive complex testing of the power plant as a whole.

Around 1962–1963 Work on the nuclear propulsion problem was headed by NII-1, which has a powerful experimental base and excellent personnel. They only lacked uranium technology, as well as nuclear scientists. With the involvement of NII-9, and then IPPE, a cooperation was formed, which took as its ideology the creation of a minimum thrust (about 3.6 tf), but “real” summer engine with a “straight-through” reactor IR-100 (test or research, 100 MW, chief designer - Yu.A. Treskin). Supported by government regulations, NII-1 built electric arc stands that invariably amazed the imagination - dozens of 6-8 m high cylinders, huge horizontal chambers with a power of over 80 kW, armored glass in boxes. Meeting participants were inspired by colorful posters with flight plans to the Moon, Mars, etc. It was assumed that in the process of creating and testing the nuclear propulsion engine, design, technological, and physical issues would be resolved.

According to R. Kotelnikov, the matter, unfortunately, was complicated by the not very clear position of the rocket scientists. The Ministry of General Engineering (MOM) had great difficulties in financing the testing program and the construction of the test bench base. It seemed that the IOM did not have the desire or capacity to advance the NRD program.

By the end of the 1960s, support for NII-1's competitors - IAE, PNITI and NII-8 - was much more serious. The Ministry of Medium Engineering ("nuclear scientists") actively supported their development; the IVG “loop” reactor (with a core and rod-type central channel assemblies developed by NII-9) eventually came to the fore by the beginning of the 70s; testing of fuel assemblies began there.

Now, 30 years later, it seems that the IAE line was more correct: first - a reliable “earthly” loop - testing of fuel rods and assemblies, and then the creation of a flight nuclear propulsion engine required power. But then it seemed that it was possible to very quickly make a real engine, albeit a small one... However, since life has shown that there was no objective (or even subjective) need for such an engine (to this we can also add that the seriousness of the negative aspects of this direction, for example international agreements on nuclear devices in space, was initially greatly underestimated), then a fundamental program, the goals of which were not narrow and specific, turned out to be correspondingly more correct and productive.

On July 1, 1965, the preliminary design of the IR-20-100 reactor was reviewed. The culmination was the release of the technical design of the IR-100 fuel assemblies (1967), consisting of 100 rods (UC-ZrC-NbC and UC-ZrC-C for the inlet sections and UC-ZrC-NbC for the outlet). NII-9 was ready to produce a large batch of core elements for the future IR-100 core. The project was very progressive: after about 10 years, practically without significant changes, it was used in the area of ​​​​the 11B91 apparatus, and even now all the main solutions are preserved in assemblies of similar reactors for other purposes, with a completely different degree of calculation and experimental justification.

The “rocket” part of the first domestic nuclear RD-0410 was developed at the Voronezh Design Bureau of Chemical Automation (KBHA), the “reactor” part (neutron reactor and radiation safety issues) - by the Institute of Physics and Energy (Obninsk) and the Kurchatov Institute of Atomic Energy.

KBHA is known for its work in the field of liquid propellant rocket engines for ballistic missiles, KA and RN. About 60 samples were developed here, 30 of which were brought to mass production. By 1986, KBHA had created the country's most powerful single-chamber oxygen-hydrogen engine RD-0120 with a thrust of 200 tf, which was used as a propulsion engine in the second stage of the Energia-Buran complex. Nuclear RD-0410 was created jointly with many defense enterprises, design bureaus and research institutes.

According to the accepted concept, liquid hydrogen and hexane (an inhibitory additive that reduces the hydrogenation of carbides and increases the life of fuel elements) were supplied using a TNA into a heterogeneous thermal neutron reactor with fuel assemblies surrounded by a zirconium hydride moderator. Their shells were cooled with hydrogen. The reflector had drives for rotating the absorption elements (boron carbide cylinders). The pump included a three-stage centrifugal pump and a single-stage axial turbine.

In five years, from 1966 to 1971, the foundations of reactor-engine technology were created, and a few years later a powerful experimental base called “expedition No. 10” was put into operation, subsequently the experimental expedition of NPO “Luch” at the Semipalatinsk nuclear test site .
Particular difficulties were encountered during testing. It was impossible to use conventional stands for launching a full-scale nuclear rocket engine due to radiation. It was decided to test the reactor at the nuclear test site in Semipalatinsk, and the “rocket part” at NIIkhimmash (Zagorsk, now Sergiev Posad).

To study intra-chamber processes, more than 250 tests were performed on 30 “cold engines” (without a reactor). The combustion chamber of the oxygen-hydrogen rocket engine 11D56 developed by KBKhimmash (chief designer - A.M. Isaev) was used as a model heating element. The maximum operating time was 13 thousand seconds with an declared resource of 3600 seconds.

To test the reactor at the Semipalatinsk test site, two special shafts with underground service premises were built. One of the shafts was connected to an underground reservoir for compressed hydrogen gas. The use of liquid hydrogen was abandoned for financial reasons.

In 1976, the first power start-up of the IVG-1 reactor was carried out. At the same time, a stand was created at the OE to test the “propulsion” version of the IR-100 reactor, and a few years later it was tested at different powers (one of the IR-100s was subsequently converted into a materials science research reactor low power, which still works).

Before the experimental launch, the reactor was lowered into the shaft using a surface-mounted gantry crane. After starting the reactor, hydrogen entered the “boiler” from below, heated up to 3000 K and burst out of the shaft in a fiery stream. Despite the insignificant radioactivity of the escaping gases, it was not allowed to be outside within a radius of one and a half kilometers from the test site during the day. It was impossible to approach the mine itself for a month. One and a half kilometers underground tunnel led from the safe zone first to one bunker, and from there to another, located near the mines. The specialists moved along these unique “corridors.”

Ievlev Vitaly Mikhailovich

The results of experiments carried out with the reactor in 1978–1981 confirmed the correctness of the design solutions. In principle, the YARD was created. All that remained was to connect the two parts and conduct comprehensive tests.

Around 1985, RD-0410 (according to a different designation system 11B91) could have made its first space flight. But for this it was necessary to develop an accelerating unit based on it. Unfortunately, this work was not ordered to any space design bureau, and there are many reasons for this. The main one is the so-called Perestroika. Rash steps led to the fact that the entire space industry instantly found itself “in disgrace” and in 1988, work on nuclear propulsion in the USSR (then the USSR still existed) was stopped. This happened not because of technical problems, but for momentary ideological considerations. And in 1990, the ideological inspirer of nuclear-powered rocket engines programs in the USSR, Vitaly Mikhailovich Ievlev, died...

What major successes have the developers achieved in creating the “A” nuclear power propulsion system?

More than one and a half dozen full-scale tests were carried out on the IVG-1 reactor, and the following results were obtained: maximum hydrogen temperature - 3100 K, specific impulse - 925 sec, specific heat release up to 10 MW/l, total resource more than 4000 sec with consecutive 10 reactor starts. These results significantly exceed American achievements in graphite zones.

It should be noted that during the entire period of NRE testing, despite the open exhaust, the yield of radioactive fission fragments did not exceed permissible standards either at the test site or outside it and was not registered on the territory of neighboring states.

The most important result of the work was the creation of domestic technology for such reactors, the production of new refractory materials, and the fact of creating a reactor-engine gave rise to a number of new projects and ideas.

Although the further development of such nuclear propulsion engines was suspended, the achievements obtained are unique not only in our country, but also in the world. This has been confirmed repeatedly in last years at international symposiums on space energy, as well as at meetings of domestic and American specialists (at the latter it was recognized that the IVG reactor stand is the only operational test apparatus in the world today that can play an important role in the experimental testing of fuel assemblies and nuclear power plants).

Be careful there are a lot of letters.

A flight model of a spacecraft with a nuclear propulsion system (NPP) is planned to be created in Russia by 2025. The corresponding work is included in the draft Federal Space Program for 2016–2025 (FKP-25), sent by Roscosmos for approval to the ministries.

Nuclear power systems are considered the main promising sources of energy in space when planning large-scale interplanetary expeditions. In the future, the nuclear power plant, which is currently being created by Rosatom enterprises, will be able to provide megawatt power in space.

All work on the creation of a nuclear power plant is proceeding in accordance with the planned deadlines. We can say with a high degree of confidence that the work will be completed on time, provided for by the target program,” says Andrey Ivanov, project manager of the communications department of the Rosatom state corporation.

Behind Lately Within the framework of the project, two important stages have been completed: a unique design of the fuel element has been created, ensuring operability under conditions of high temperatures, large temperature gradients, and high-dose radiation. Technological tests of the reactor vessel of the future space power unit have also been successfully completed. As part of these tests, the housing was subjected to overpressure and 3D measurements were taken in the base metal, circumferential weld and tapered transition areas.

Operating principle. History of creation.

There are no fundamental difficulties with a nuclear reactor for space applications. In the period from 1962 to 1993, our country accumulated a wealth of experience in the production of similar installations. Similar work was carried out in the USA. Since the early 1960s, several types of electric propulsion engines have been developed in the world: ion, stationary plasma, anode layer engine, pulsed plasma engine, magnetoplasma, magnetoplasmodynamic.

Work on creating nuclear engines for spacecraft was actively carried out in the USSR and the USA in the last century: the Americans closed the project in 1994, the USSR - in 1988. The closure of work was largely facilitated by the Chernobyl disaster, which negatively affected public opinion regarding the use of nuclear energy. In addition, tests of nuclear installations in space did not always proceed as planned: in 1978, the Soviet satellite Kosmos-954 entered the atmosphere and disintegrated, scattering thousands of radioactive fragments over an area of ​​100 thousand square meters. km in northwestern Canada. The Soviet Union paid Canada monetary compensation in the amount of more than $10 million.

In May 1988, two organizations - the Federation of American Scientists and the Committee of Soviet Scientists for Peace Against the Nuclear Threat - made a joint proposal to ban the use of nuclear energy in space. That proposal did not receive any formal consequences, but since then no country has launched spacecraft with nuclear power plants on board.

The great advantages of the project are practically important operational characteristics - a long service life (10 years of operation), a significant overhaul interval and a long operating time on one switch.

In 2010, technical proposals for the project were formulated. Design began this year.

The nuclear power plant contains three main devices: 1) a reactor installation with a working fluid and auxiliary devices (heat exchanger-recuperator and turbogenerator-compressor); 2) electric rocket propulsion system; 3) refrigerator-emitter.

Reactor.

From a physical point of view, this is a compact gas-cooled fast neutron reactor.
The fuel used is a compound (dioxide or carbonitride) of uranium, but since the design must be very compact, the uranium has a higher enrichment in the isotope 235 than in fuel rods in conventional (civilian) nuclear plants, perhaps above 20%. And their shell is a monocrystalline alloy refractory metals based on molybdenum.

This fuel will have to work at very high temperatures. Therefore, it was necessary to choose materials that could contain negative factors associated with temperature, and at the same time allow the fuel to perform its main function - to heat the coolant gas, which will be used to produce electricity.

Fridge.

Cooling of gas during the operation of a nuclear installation is absolutely necessary. How to dump heat in outer space? The only possibility is cooling by radiation. The heated surface in the void cools, emitting electromagnetic waves in a wide range, including visible light. The uniqueness of the project is the use of a special coolant - a helium-xenon mixture. The installation ensures a high efficiency.

Engine.

The operating principle of the ion engine is as follows. In the gas-discharge chamber, a rarefied plasma is created using anodes and a cathode block located in a magnetic field. From it, the ions of the working fluid (xenon or other substance) are “pulled” by the emission electrode and accelerated in the gap between it and the accelerating electrode.

To implement the plan, 17 billion rubles were promised between 2010 and 2018. Of these funds, 7.245 billion rubles were intended for the Rosatom state corporation to create the reactor itself. Another 3.955 billion - FSUE "Keldysh Center" for the creation of a nuclear power propulsion plant. Another 5.8 billion rubles will go to RSC Energia, where, within the same time frame, the working appearance of the entire transport and energy module will have to be formed.

According to plans, by the end of 2017, a nuclear power propulsion system will be prepared to complete the transport and energy module (interplanetary transfer module). By the end of 2018, the nuclear power plant will be prepared for flight tests. The project is financed from the federal budget.

It is no secret that work on the creation of nuclear rocket engines began in the USA and the USSR back in the 60s of the last century. How far have they come? And what problems did you encounter along the way?

Anatoly Koroteev: Indeed, work on the use of nuclear energy in space was started and actively carried out here and in the USA in the 1960-70s.

Initially, the task was set to create rocket engines that, instead of the chemical energy of combustion of fuel and oxidizer, would use heating of hydrogen to a temperature of about 3000 degrees. But it turned out that such a direct path was still ineffective. We get high thrust for a short time, but at the same time we emit a jet, which in the event of abnormal operation of the reactor may turn out to be radioactively contaminated.

Some experience was accumulated, but neither we nor the Americans were able to create reliable engines. They worked, but not much, because heating hydrogen to 3000 degrees in a nuclear reactor is a serious task. In addition, environmental problems arose during ground tests of such engines, since radioactive jets were released into the atmosphere. It is no longer a secret that such work was carried out at the Semipalatinsk test site, specially prepared for nuclear testing, which remained in Kazakhstan.

That is, two parameters turned out to be critical - extreme temperature and radiation emissions?

Anatoly Koroteev: In general, yes. Due to these and some other reasons, work in our country and in the USA was stopped or suspended - this can be assessed in different ways. And it seemed unreasonable to us to resume them in such a, I would say, head-on manner, in order to make a nuclear engine with all the already mentioned shortcomings. We proposed a completely different approach. It differs from the old one in the same way that a hybrid car differs from a regular one. In a regular car, the engine turns the wheels, but in hybrid cars, electricity is generated from the engine, and this electricity turns the wheels. That is, some kind of intermediate power station is being created.

So we proposed a scheme in which the space reactor does not heat the jet ejected from it, but generates electricity. Hot gas from the reactor turns the turbine, the turbine turns the electric generator and the compressor, which circulates the working fluid in a closed loop. The generator produces electricity for the plasma engine with a specific thrust 20 times higher than that of chemical analogues.

Tricky scheme. Essentially, this is a mini-nuclear power plant in space. And what are its advantages over a ramjet nuclear engine?

Anatoly Koroteev: The main thing is that the jet coming out of the new engine will not be radioactive, since a completely different working fluid passes through the reactor, which is contained in a closed circuit.

In addition, with this scheme we do not need to heat hydrogen to prohibitive values: an inert working fluid circulates in the reactor, which heats up to 1500 degrees. We're making things really easy for ourselves. And as a result, we will increase the specific thrust not by two times, but by 20 times compared to chemical engines.

Another thing is also important: there is no need for complex full-scale tests, which require the infrastructure of the former Semipalatinsk test site, in particular, the test bench base that remains in the city of Kurchatov.

In our case, all the necessary tests can be carried out on Russian territory, without being drawn into long international negotiations on the use of nuclear energy outside the borders of one’s state.

Is similar work currently underway in other countries?

Anatoly Koroteev: I had a meeting with the deputy head of NASA, we discussed issues related to returning to work on nuclear energy in space, and he said that the Americans are showing great interest in this.

It is quite possible that China may respond with active actions on its part, so we need to work quickly. And not just for the sake of being half a step ahead of someone.

We need to work quickly, first of all, so that in the emerging international cooperation, and de facto it is being formed, we looked decent.

I do not rule out that in the near future an international program for a nuclear space power plant, similar to the controlled thermonuclear fusion program currently being implemented, may be initiated.

One could begin this article with a traditional passage about how science fiction writers put forward bold ideas, and scientists then bring them to life. You can, but you don’t want to write with stamps. It is better to remember that modern rocket engines, solid fuel and liquid, have more than unsatisfactory characteristics for flights over relatively long distances. They allow you to launch cargo into Earth orbit and deliver something to the Moon, although such a flight is more expensive. But flying to Mars with such engines is no longer easy. Give them fuel and oxidizer in the required quantities. And these volumes are directly proportional to the distance that must be overcome.

An alternative to traditional chemical rocket engines are electric, plasma and nuclear engines. Of all the alternative engines, only one system has reached the stage of engine development - nuclear (Nuclear Reaction Engine). In the Soviet Union and the United States, work began on the creation of nuclear rocket engines back in the 50s of the last century. The Americans were working on both options for such a power plant: reactive and pulsed. The first concept involves heating the working fluid using a nuclear reactor and then releasing it through nozzles. The pulse nuclear propulsion engine, in turn, propels the spacecraft through successive explosions of small amounts of nuclear fuel.

Also in the USA, the Orion project was invented, combining both versions of the nuclear powered engine. This was done in the following way: small nuclear charges with a capacity of about 100 tons of TNT were ejected from the tail of the ship. Metal discs were fired after them. At a distance from the ship, the charge was detonated, the disk evaporated, and the substance scattered in different directions. Part of it fell into the reinforced tail section of the ship and moved it forward. A small increase in thrust should have been provided by the evaporation of the plate taking the blows. The unit cost of such a flight should have been only 150 then dollars per kilogram of payload.

It even got to the point of testing: experience showed that movement with the help of successive impulses is possible, as is the creation of a stern plate of sufficient strength. But the Orion project was closed in 1965 as unpromising. However, this is so far the only existing concept that can allow expeditions at least across the solar system.

It was only possible to reach the construction of a prototype with a nuclear-powered rocket engine. These were the Soviet RD-0410 and the American NERVA. They worked on the same principle: in a “conventional” nuclear reactor, the working fluid is heated, which, when ejected from the nozzles, creates thrust. The working fluid of both engines was liquid hydrogen, but the Soviet one used heptane as an auxiliary substance.

The thrust of the RD-0410 was 3.5 tons, NERVA gave almost 34, but it also had large dimensions: 43.7 meters in length and 10.5 in diameter versus 3.5 and 1.6 meters, respectively, for the Soviet engine. At the same time, the American engine was three times inferior to the Soviet one in terms of resource - the RD-0410 could work for an entire hour.

However, both engines, despite their promise, also remained on Earth and did not fly anywhere. main reason the closure of both projects (NERVA in the mid-70s, RD-0410 in 1985) - money. The characteristics of chemical engines are worse than those of nuclear engines, but the cost of one launch of a ship with a nuclear propulsion engine with the same payload can be 8-12 times more than the launch of the same Soyuz with a liquid propellant engine. And this does not even take into account all the costs necessary to bring nuclear engines to the point of being suitable for practical use.

The decommissioning of “cheap” Shuttles and the recent lack of revolutionary breakthroughs in space technology requires new solutions. In April of this year, the then head of Roscosmos A. Perminov announced his intention to develop and put into operation a completely new nuclear propulsion system. This is precisely what, in the opinion of Roscosmos, should radically improve the “situation” in the entire world cosmonautics. Now it has become clear who should become the next revolutionaries in astronautics: the development of nuclear propulsion engines will be carried out by the Keldysh Center Federal State Unitary Enterprise. CEO enterprise A. Koroteev has already pleased the public that the preliminary design of the spacecraft for the new nuclear propulsion engine will be ready next year. The engine design should be ready by 2019, with testing scheduled for 2025.

The complex was called TEM - transport and energy module. It will carry a gas-cooled nuclear reactor. The direct propulsion system has not yet been decided: either it will be a jet engine like the RD-0410, or an electric rocket engine (ERE). However, the latter type has not yet been widely used anywhere in the world: only three spacecraft were equipped with them. But the fact that the reactor can power not only the engine, but also many other units, or even use the entire TEM as a space power plant, speaks in favor of the electric propulsion engine.

Already at the end of this decade, a nuclear-powered spacecraft for interplanetary travel may be created in Russia. And this will dramatically change the situation both in near-Earth space and on the Earth itself.

The nuclear power plant (NPP) will be ready for flight in 2018. This was announced by the director of the Keldysh Center, academician Anatoly Koroteev. “We must prepare the first sample (of a megawatt-class nuclear power plant. – Expert Online’s note) for flight tests in 2018. Whether she will fly or not is another matter, there may be a queue, but she must be ready to fly,” RIA Novosti reported his words. The above means that one of the most ambitious Soviet-Russian projects in the field of space exploration is entering the phase of immediate practical implementation.

The essence of this project, whose roots go back to the middle of the last century, is this. Now flights into near-Earth space are carried out on rockets that move due to the combustion of liquid or liquid in their engines. solid fuel. Essentially, this is the same engine as in a car. Only in a car does gasoline, when burned, push the pistons in the cylinders, transferring its energy through them to the wheels. And in a rocket engine, burning kerosene or heptyl directly pushes the rocket forward.

Over the past half century, this rocket technology has been perfected all over the world to the smallest detail. But the rocket scientists themselves admit that . Improvement - yes, it is necessary. Trying to increase the payload of rockets from the current 23 tons to 100 and even 150 tons based on “improved” combustion engines - yes, you need to try. But this is a dead end from an evolutionary point of view. " No matter how much rocket engine specialists around the world work, the maximum effect we get will be calculated in fractions of a percent. Roughly speaking, everything has been squeezed out of existing rocket engines, be they liquid or solid fuel, and attempts to increase thrust and specific impulse are simply futile. Nuclear power propulsion systems provide a multifold increase. Using the example of a flight to Mars, now it takes one and a half to two years to fly there and back, but it will be possible to fly in two to four months "- the former head of the Russian Federal Space Agency assessed the situation at one time Anatoly Perminov.

Therefore, back in 2010, the then President of Russia, and now Prime Minister Dmitry Medvedev By the end of this decade, an order was given to create in our country a space transport and energy module based on a megawatt-class nuclear power plant. It is planned to allocate 17 billion rubles from the federal budget, Roscosmos and Rosatom for the development of this project until 2018. 7.2 billion of this amount was allocated to the Rosatom state corporation for the creation of a reactor plant (this is being done by the Dollezhal Research and Design Institute of Energy Engineering), 4 billion - to the Keldysh Center for the creation of a nuclear power propulsion plant. 5.8 billion rubles are allocated by RSC Energia to create a transport and energy module, that is, in other words, a rocket ship.

Naturally, all this work is not done in a vacuum. From 1970 to 1988, the USSR alone launched more than three dozen spy satellites into space, equipped with low-power nuclear power plants such as Buk and Topaz. They were used to create an all-weather system for monitoring surface targets throughout the World Ocean and issuing target designation with transmission to weapon carriers or command posts - the Legend naval space reconnaissance and target designation system (1978).

NASA and American companies that produce spacecraft and their delivery vehicles have not been able to create a nuclear reactor that would operate stably in space during this time, although they tried three times. Therefore, in 1988, a ban was passed through the UN on the use of spacecraft with nuclear power propulsion systems, and the production of satellites of the US-A type with nuclear propulsion on board in the Soviet Union was discontinued.

In parallel, in the 60-70s of the last century, the Keldysh Center carried out active work on the creation of an ion engine (electroplasma engine), which is most suitable for creating a high-power propulsion system operating on nuclear fuel. The reactor produces heat, which is converted into electricity by a generator. With the help of electricity, the inert gas xenon in such an engine is first ionized, and then positively charged particles (positive xenon ions) are accelerated in an electrostatic field to a given speed and create thrust when leaving the engine. This is the operating principle of the ion engine, a prototype of which has already been created at the Keldysh Center.

« In the 90s of the 20th century, we at the Keldysh Center resumed work on ion engines. Now a new cooperation must be created for such a powerful project. There is already a prototype of an ion engine on which basic technological and Constructive decisions. But standard products still need to be created. We have a set deadline - by 2018 the product should be ready for flight tests, and by 2015 the main engine testing should be completed. Next - life tests and tests of the entire unit as a whole.“, noted last year the head of the electrophysics department of the Research Center named after M.V. Keldysh, Professor, Faculty of Aerophysics and Space Research, MIPT Oleg Gorshkov.

What is the practical benefit for Russia from these developments? This benefit far exceeds the 17 billion rubles that the state intends to spend by 2018 on creating a launch vehicle with a nuclear power plant on board with a capacity of 1 MW. Firstly, this is a dramatic expansion of the capabilities of our country and humanity in general. A nuclear-powered spacecraft provides real opportunities for people to accomplish things on other planets. Now many countries have such ships. They also resumed in the United States in 2003, after the Americans received two samples of Russian satellites with nuclear power plants.

However, despite this, a member of the NASA special commission on manned flights Edward Crowley for example, he believes that a ship for an international flight to Mars should have Russian nuclear engines. " Russian experience in the development of nuclear engines is in demand. I think Russia has a lot of experience both in the development of rocket engines and in nuclear technology. She also has extensive experience in human adaptation to space conditions, since Russian cosmonauts made very long flights “,” Crowley told reporters last spring after a lecture at Moscow State University on American plans for manned space exploration.

Secondly, such ships make it possible to sharply intensify activity in near-Earth space and provide a real opportunity to begin the colonization of the Moon (there are already projects for the construction of nuclear power plants on the Earth’s satellite). " The use of nuclear propulsion systems is being considered for large manned systems, rather than for small spacecraft, which can fly on other types of installations using ion engines or solar wind energy. Nuclear propulsion systems with ion engines can be used on an interorbital reusable tug. For example, transport cargo between low and high orbits, and fly to asteroids. You can create a reusable lunar tug or send an expedition to Mars“, says Professor Oleg Gorshkov. Ships like these are dramatically changing the economics of space exploration. According to calculations by RSC Energia specialists, a nuclear-powered launch vehicle reduces the cost of launching a payload into lunar orbit by more than half compared to liquid rocket engines.

Third, these are new materials and technologies that will be created during the implementation of this project and then introduced into other industries - metallurgy, mechanical engineering, etc. That is, this is one of those breakthrough projects that can really push both the Russian and global economies forward.