The first projects to create permanent bases on the moon were developed in the USSR and the USA back in the 1960s. To implement such projects requires tremendous resources and efforts. At present, there are no weighty arguments in favor of a peaceful lunar base (questions of science and prestige are not, given the enormous costs that do not have adequate returns). Arguments about the economic value of the lunar base are unfounded, and the extraction of helium - 3 is not of interest so far (due to the lack of industrial fusion reactors).
Thus, the main obstacle is the practical uselessness of projects for the peaceful exploration of the moon (that is, it is possible, but not necessary to build a lunar base). Currently, the main incentive may be exclusively military issues. The most obvious is the possibility of using the moon as a location for nuclear missiles. However, the combat use of lunar-based nuclear missiles is justified only in the context of a global military conflict (which may not take place in the foreseeable future). In addition, there are international agreements on the non-nuclear status of outer space (the violation of which may do the country more harm than good).
In this regard, we consider the concept of a lunar base, designed to accommodate non-nuclear weapons (in particular, artillery systems). The use of these systems is possible in the conduct of hostilities of any intensity and scale. The advantage of the location of such systems on the moon is the possibility of exposure to any point on Earth in the shortest possible time. For this, it will not be necessary to solve the complex tasks of moving major military forces and weapons systems to the conflict zone (which is not always possible for a long time).
The average distance between the centers of the Moon and the Earth is ~ 384 thousand. Km. The second cosmic velocity for the moon is ~ 2400 m / s. At a distance of ~ 38 thousand km from the center of the moon (in the direction of the Earth), the lunar and terrestrial forces balance each other. When starting from the surface of the moon, the achievement of this point (with balanced forces) is possible at an initial speed of ~ 2280 m / s. Thus, if the moon cannon provides acceleration of the projectile to the required initial speed (in the direction of the Earth), then the projectile will fall to the Earth.
By increasing the mass of the powder charge, the aforementioned initial projectile velocity cannot be provided. The way out is to use micro-jet engines to increase the speed of the projectile (after the projectile leaves the barrel). Consider this possibility on the example of experimental tank guns 50L "Vityaz" http://www.oborona.co.uk/kbao.pdf.
This 125 mm caliber gun provides the projectile with an 7 kg barrel weight, the initial speed of 2030 m / s. When pure hydrogen peroxide is used as a single-component rocket fuel (specific impulse ~ 150 s), the mass of fuel required for the operation of a micro-jet engine will be ~ 1,1 kg (~ 16% of the projectile’s barrel mass). As a result of the work of the micro-jet engine, the velocity of the projectile will increase to ~ 2280 m / s, and the projectile will be able to overcome the lunar force of the moon (when this gun is placed on the moon).
Thus, in principle, classical artillery systems based on gunpowder can be used to arm the lunar base (provided that the projectiles are additionally accelerated by micro-jet engines). An effective means of delivery are also rockets. In our case, it is proposed to use pneumatic electric artillery systems. http://n-t.ru/tp/ts/oo.htm.
For pneumoelectric artillery systems of the lunar base, it is proposed to use oxygen under pressure (or a mixture of oxygen with helium) as a propelling agent, and a chemical reaction between oxygen and aluminum as a source of thermal energy.
Pneumoelectric artillery systems are capable of providing a very high initial velocity of the projectile. In addition, the production of some components (for example, pneumoelectric propellant charges) can be organized on the lunar base with the least effort. The lunar soil has all the necessary elements for this (in some samples the oxygen content reaches 44%, aluminum 13%). Artillery systems are much cheaper than rockets, i.e., much easier to manufacture (which simplifies the task of organizing this production on the moon).
In the powder and pneumatic electric gun, the absolute value of the maximum pressure can have approximately the same values (because limited by the strength of the barrel). In the powder gun after the combustion of the powder charge, the process of expanding the powder gases continues without heat exchange (adiabatic process). In the pneumoelectric gun (after the combustion of the aluminum fuel element) a mixture of gaseous oxygen and aluminum oxide particles (heated to a high temperature) is formed. Therefore, the process of expanding oxygen will no longer be adiabatic (since heat is transferred from aluminum oxide particles). As a result of a slow decrease in the temperature of oxygen, its pressure at the muzzle will be greater (with the same degree of expansion as powder gases), and the initial velocity of the projectile is higher. Thus, the internal ballistics of pneumoelectric weapons significantly different from the internal ballistics of classic firearms.
It is necessary to emphasize the fact that for the defeat of targets on Earth it is not necessary to use artillery systems of super-large caliber. The pneumatic electric gun can have the following parameters: barrel length 6 m, caliber 125 mm, barrel weight of the projectile 7 kg, initial projectile speed ~ 2400 m / s. After passing through the critical point (with balanced forces of force), the velocity of the projectile will increase due to gravity and, in the absence of the atmosphere, could reach ~ 11000 m / s. Loss on aerodynamic air resistance can be estimated at ~ 3000 m / s (when moving along a ballistic trajectory vertical to the surface of the Earth). As a result, when falling to the Earth, the velocity of the projectile can be ~ 8000 m / s.
The projectile may consist of a heavy core (5 kg) and a light non-detachable body (2 kg). The shell of the projectile ensures the retention of the core in the barrel and serves as a kind of piston, taking gas pressure when fired and ensuring the acceleration of the entire projectile. The shell of the projectile also protects the core from burning (after the projectile performs the Moon – Earth flight and enters the atmosphere). As the projectile body is heated, it is made of heat-shielding materials, which leads to a decrease in the diameter of the projectile and a decrease in the aerodynamic resistance of atmospheric air.
A well-streamlined projectile forms a relatively weak shock wave reflecting ~ 50% thermal energy into the atmosphere. If we consider that the mass (and speed) of the projectile decreases from 7 kg (~ 11 km / s) to 5 kg (~ 8 km / s), the total amount of heat released will be ~ 200 MJ. Thus, half of the heat (~ 100 MJ) must be "blocked" with the help of a heat-shielding shell of the projectile, in which the processes of melting, evaporation, sublimation and chemical reactions take place. Materials for the manufacture of the body of the projectile can be fiberglass, other plastics based on organic (or silicone) binders, carbon compositions, porous metals with bound (not hermetic) cells, etc.
To characterize heat-shielding materials, the concept of effective enthalpy is used (the amount of heat that can be “blocked” when a unit of mass of a coating is destroyed). In our case, the mass of the heat shield (projectile body) is 2 kg, the amount of "blocked" heat ~ 100 MJ. The effective enthalpy of the materials from which it is necessary to manufacture the shell of the projectile should be ~ 50 MJ / kg (this level of thermal protection can be achieved with the help of existing materials).
At a speed of ~ 8 km / s, the kinetic energy of a projectile with a mass of 5 kg will be ~ 160 MJ. This energy is comparable to the kinetic energy of the projectiles of the main caliber (406 mm) of Iowa type battleships (at the time of the hit of these large-caliber projectiles at the target). The armor penetration capability of the main caliber of an Iowa type battleship is only ~ 400 mm of armor. For comparison, we note that the armor penetration capability of a high-speed tank fires with a mass of 5 kg is ~ 600 mm of armor. The armor penetration of a lunar shell will be even greater, since its speed (~ 8 km / s) is already comparable to the speed of a cumulative jet (~ 10 km / s).
Given the excessive armor penetration, for the manufacture of a lunar shell, you can use light alloys, such as aluminum. If necessary, heavy metals (tungsten, uranium, etc.) can be used. An additional effect can be achieved in the case of manufacturing a projectile from enriched uranium metal (after being hit by such a projectile, the ship can be decommissioned as a result of strong radioactive contamination from the explosion products).
In the process of hitting a target during a kinetic explosion, the projectile can completely go into a fine state or even evaporate (in the extreme case). With the kinetic energy of the projectile ~ 160 MJ, this will require only ~ 53 MJ of heat (specific heat of evaporation of aluminum ~ 10,5 MJ / kg). The products of a kinetic explosion can enter into a chemical reaction with the oxygen of the air (enhancing the armor ‑ action of the projectile). With the specific heat of combustion of aluminum ~ 31 MJ / kg, the instantaneous release of thermal energy as a result of a chemical reaction can reach ~ 155 MJ (without taking into account the thermal energy of combustion of metal microparticles of destroyed armor and ship structures). The total heat energy of the explosion of the projectile can be ~ 315 MJ (which is equivalent to the thermal energy of the explosion ~ 75 kg of TNT). Note that the high-explosive projectile of the main caliber (406 mm) of the Iowa type battleship contains only ~ 70 kg of explosive.
Thus, the 125-mm lunar cannon projectile exceeds the armor-piercing projectile of the 406-mm caliber by armor penetration, and is comparable to the high-explosive projectile of the 406-mm caliber in explosive action. This suggests that with the help of shells fired from the moon cannon, it is possible to destroy a military or transport ship of any class (including a heavy attack aircraft carrier). Moon-based artillery systems can be used as anti-satellite weapons. Possible targets are ground infrastructure, military and production facilities, etc. If the projectile's mass is insufficient to destroy any targets, then this difficulty can be overcome with the help of artillery systems of a larger caliber.
In modern 125 caliber guns, the mass of the powder propellant charge does not exceed 10 kg. Pressure is determined by the temperature and concentration of gas molecules. The molecular mass of oxygen is 16 g / mol, and the average molecular mass of powder gases is ~ 30 g / mol. Thus, in the first approximation, the amount of oxygen can be ~ 5 kg (for use as a propellant).
The velocity of the expanding gases is approximately equal to the velocity of the projectile. When firing modern cannons with high-speed armor-piercing piercing shells, the kinetic energy of the projectile and the kinetic energy of the powder gases in the total can exceed 70% of the initial energy of the burning powder charge.
With this in mind, it is possible to approximately estimate the amount of energy required to accelerate the projectile (and the combustion products of a pneumoelectric propellant charge) to a speed of ~ 2400 m / s (the average velocity of oxygen molecules is significantly higher than the average velocity of powder gas molecules). This amount of energy will be ~ 65 MJ and can be obtained by burning ~ 2,1 kg of aluminum (with the participation of ~ 1,9 kg of oxygen). Thus, the total mass of a pneumoelectric propellant charge can be ~ 9 kg (of which ~ 2,1 kg aluminum and ~ 6,9 kg oxygen). With a pressure of compressed oxygen ~ 500 atmospheres, its volume will be ~ 10,5 liters.
Preparation for the shot is as follows. Through the breech into the oxygen chamber is inserted projectile. A burning element is placed between the rear of the projectile and the shutter. The shutter closes, and then oxygen is supplied to the oxygen chamber from the high-pressure tank (to prevent the oxygen temperature from rising as a result of its compression).
The oxygen chamber is an extension in the breech (in the form of a sphere). The sphere has a diameter of ~ 0,3 m. Its volume is ~ 14,1 liters. After loading the cannon with a projectile, the volume of the oxygen chamber is reduced to ~ 10,5 liters. The oxygen chamber is part of the trunk and has an entrance (from the breech side) and an exit (in the direction of the muzzle). The length (diameter) of the oxygen chamber is less than the length of the projectile. Therefore, in preparation for the shot, the projectile simultaneously blocks the inlet and outlet openings (thereby sealing the oxygen chamber). Thus, the oxygen pressure acts on the side surfaces of the projectile (perpendicular to the longitudinal axis of the projectile).
The diameter of the inlet and outlet holes coincides with the diameter of the projectile. With a gap width between the body of the projectile and the surface of the barrel 0,1 mm (the slot area will be 0,4 cm ²). The breech block of the barrel is additionally blocked by a bolt, so the main leakage occurs in the direction of the muzzle hole of the gun barrel. At the beginning of the gap, the velocity of the oxygen flow does not exceed the speed of sound (~ 330 m / s at 30 ° C). Thus, the maximum possible level of oxygen leakage will be 190 helium servings (~ 1,3 kg each). If the barrel survivability is less than 200 shots, the delivery of helium from the Earth (and then using it as one of the components of a pneumoelectric propellant charge) is economically justified. In the distant future, helium-4 may be produced on the Moon as a by-product (when extracting the potential fuel of the future thermonuclear energy of helium-3).
When delivering helium from the Earth, the use of alloys based on noble metals does not lose its meaning. In the event of a disruption in the supply from the Earth, the supply of helium may end and it will be necessary to return to the use of pure oxygen (obtained from the lunar soil). In addition, under no circumstances will aluminum have time to burn instantly, and some of the oxygen will come into contact with the inner surface of the gun barrel (even in the case of using a gas mixture of oxygen with helium). Therefore, in any case, there remains a need to use chemically inactive alloys (in particular, based on noble metals).
The time of flight of the projectile is several tens of hours (this time can vary in very wide limits, depending on the initial velocity of the projectile). In this regard, the concept of using a lunar gun provides for the start of firing even before the start of the proposed military operation. If during the approach of the projectile to the Earth, the need to destroy any target remains, the projectile is aimed at this target. If during the flight of the projectile it is decided that it is inexpedient to destroy targets, the projectile can be brought to the point where it will not cause harm. In the case of the start of active hostilities, firing will be carried out systematically (at short intervals), and the projectiles will be aimed at the targets hit as the projectiles approach the Earth.
At the stage of the Moon-Earth flight, projectiles can be aimed at a target using micro-jet engines. Given the long flight time of the projectile, micro-jet engines of the guidance system can have extremely low thrust and low specific impulse. At the atmospheric part of the flight, the projectile can be stabilized using aerodynamic surfaces by rotating the projectile body or using a gyroscope inside the projectile.
On spacecraft, as a rule, micro-jet engines operating on compressed gas are used. In our case, the use of compressed gas will lead to an increase in the size of the projectile, which will increase the aerodynamic resistance of air in the atmospheric flight phase. Therefore, it is advisable to use micro-reactive engines operating on either a single-component fuel (for example, hydrogen peroxide) or on a two-component, self-igniting fuel (for example, dimethylhydrazine and nitric acid). The inclusion of micro-jet engines is carried out by a special signal from an internal or external control system.
The significance of the goal should justify the use of lunar-based weapons systems on it. In addition, the projectile has a small size, great speed, when passing through the atmosphere around the projectile a cloud of plasma is formed, etc. All these factors complicate the creation of self-guided projectiles that work on the principle of “fired and forgotten”. Probably the best option is external control of the projectile, its guidance to the target on the space segment of the flight trajectory and the passage of the atmosphere by the projectile along a ballistic trajectory (if possible, vertical to the surface of the Earth).
Most of the atmospheric air (~ 65%) is concentrated in the near-surface layer of the atmosphere ~ 10 km thick. The duration of the passage of the projectile of this layer will be ~ 1 with. In order to deviate from the target on 1 m, a force must act in the lateral direction on the projectile, providing acceleration ~ 0,2 g. Given the large weight and small size of the projectile, any possible movement of the masses of atmospheric air is not able to significantly change the trajectory of the projectile.
According to our concept, lunar weapons systems can be used against an adversary who does not have the technical capabilities of early detection and interception. Therefore, one of the possible options for controlling the flight path is placing radio beacons on the shells. Using a radio signal, the coordinates and velocity of the projectile are determined, and by transmitting the appropriate control signals to micro-jet engines, the projectile’s flight path is corrected and aimed at the target.
In the case of the use of lunar-based artillery systems against an adversary with appropriate technical capabilities for early detection and interception of shells, it is necessary to additionally use false targets (which are also supplied with radio beacons). These beacons operate on a predetermined special program (giving signals at a certain time, changing the frequency and power of signals, etc.). Thus, the enemy will not be able to distinguish a false target from an attacking projectile due to the mere presence of a working beacon.
One of the key areas of application of moon-based artillery systems may be to support the actions of its naval fleet. The Navy solves the following classic tasks: the fight against the enemy’s naval forces, the disruption of the enemy’s sea lanes, the protection of its sea lanes, the defense of its coast from the sea, the delivery of attacks and the invasion of enemy territory from the sea, etc.
Ships are a good target for striking kinetic ammunition from space. To determine the probability of hitting a target, the concept of a circular probable deviation is used (the radius of a circle delineated around the aiming point, which 50% of shells are supposed to fall into). The width of the deck of the ship can have the following characteristic values: frigate ~ 15 m, destroyer ~ 19 m, heavy strike aircraft carrier ~ 41 m, universal landing ship ~ 43 m. Supertanker ~ 69 m. The length of the ship hull can be ignored, because its value is an order of magnitude greater than the magnitude of the circular probable deviation.
Assume that the roundabout probable deflection of the projectile is ~ 15 m. Then the probability of hitting a single projectile into the ship will be as follows: frigate ~ 0,4, destroyer ~ 0,5, heavy attack aircraft carrier ~ 0,9, universal landing ship ~ 0,9, supertanker ~ 1. Lunar-based artillery systems are able to provide invaluable support to the actions of their navy (by destroying enemy ships with a large number of shells anywhere in the world’s oceans). This circumstance may be the key to conquering global strategic dominance at sea.
In the event of a major military conflict, the enemy may attempt to destroy the lunar base. Possibilities for the delivery of military cargo to the moon are limited (therefore, the main option is to use nuclear warheads). Since the Moon does not possess an atmosphere, there is no such damaging factor of a nuclear explosion as an air shock wave. Penetrating radiation is ineffective, because On the lunar base protection against solar and space radiation is provided. Light emission is also inefficient due to the absence of the atmosphere and combustible materials. Thus, the lunar base can be destroyed only by a direct hit of a nuclear charge (with its subsequent explosion).
The passive protection option provides for placing the lunar base on the surface or below the lunar surface in several modules or buildings (distant from each other for a long distance and stable against oscillations of the lunar surface), taking camouflage measures, creating false targets, etc. The active defense option provides for a preventive attack on the enemy’s launch complexes, the destruction of the missiles at the start, during the flight to the lunar base (and these tasks can be solved using lunar-based artillery systems), etc.
Thus, from our point of view, the solution of military tasks is currently the only real opportunity for the creation and development of a lunar base. The main source of funding may be the military budget. In parallel, lunar base will be used for research in planetology, astronomy, cosmology, space biology, materials science, and other disciplines. Accordingly, some of the funding can be carried out in the framework of the development programs of these scientific and technical disciplines.
The lack of atmosphere and low gravity allows you to build on the lunar surface of the observatory, equipped with optical and radio telescopes. Maintenance and modernization of the lunar observatory is much easier than orbital. Such an observatory will allow you to explore remote areas of the universe. In addition, its tools can be used to study and monitor the Earth and near-Earth space (to obtain intelligence information, support military operations, control the trajectories of projectiles, etc.).
Thus, the presence of a base on the moon will allow it to deploy high-precision non-nuclear weapons systems that can actually be used in military conflicts of any scale (or even "anti-terrorist" operations). The use of such lunar-based systems as one of the means of warfare will significantly enhance the country's military potential. In addition, the creation and operation of the lunar base at the same time will allow us to intensively develop many scientific and technical directions, retain leadership in these areas and gain competitive advantage in the world due to this leadership.