In the
first part, we talked about how in a very realistic simulator of space battles Children of a Dead Earth looks like a battlefield, which engines are used on ships, from where they take electricity, and how they remove excess heat. In the second part we will talk about weapons and armor.
A flotilla of drones starts a rocket attack, the enemy tries to respond with anti-aircraft fireWeapons
Rockets
In our reality, there are already missiles for hitting targets in space, and they, of course, differ from atmospheric versions. In a vacuum, aerodynamic control surfaces are not needed (but orientation engines appear), and a rocket can be of any, even completely non-streamlined, form.
In the picture - the Soviet project “Fighter of satellites”. The system consisted of several stages: the fighter launching the fighter into an orbit suitable for interception, the fighter’s orbits and targets were refined at the first orbit, the fighter received corrective data, the radar approached the second orbit, and detonated fragmentation warheads hitting the target. Under the title “Flight” in the 1960s, vehicles were launched to test the maneuvering system, and in the 1970s tests were carried out with the interception and destruction of target satellites. In one test, less than 45 minutes passed from the receipt of the order to the destruction of the target.
And on this video test kinetic interceptor for the destruction of ballistic missile warheads in space. A high counter speed means that in order to destroy a target, it is enough just to collide without additional charge of explosives.
In CoaDE, rockets look almost like atmospheric, and the main reason for this is that they are not yet finalized. The rocket targeting algorithm is designed for one rotating engine located at the rear, and the control logic as in the video above cannot be implemented. Because of this, the rocket is not able to keep strictly nose to the target, so you have to cover it with armor completely. In addition, the guidance algorithm is often very uneconomical to use fuel, which is corny ends at the target, turning off the rocket and making it useless. Also, rockets do not know how to effectively distribute targets, there is no electronic warfare, and interference has so far been made at a very primitive level. And finally, the missiles are aimed at one point of the ship instead of being effectively distributed and causing damage from all sides.
The standard anti-ship warhead is a nuclear charge (for more details on the design below). In this case, a nuclear explosion in space loses the main damaging factor - the shock wave. Combined with missile guidance problems, nuclear warheads are noticeably weaker than expected - the ship can survive dozens of explosions in the immediate vicinity. But in terms of an equation with two unknowns — the damaging factors of a nuclear explosion and the effectiveness of ship's armor — it cannot be said how realistic the picture is.
We design a warhead
Why is the atomic bomb design not afraid to study at school? Because, knowing the general principles, schoolchildren will still not be able to extract radioactive ore, enrich it and undermine the charge in the right way. The atomic program requires the efforts of an entire industrialized country because high technology is needed to create a nuclear bomb. It is necessary to compress fissile material very quickly in order for an explosion to occur, and not thermal “zilch” with a very dirty result. Historically, a cannon scheme was first tested, when one charge was fired from a cannon to another, then a circular implosion scheme, where a charge was compressed by a shock wave from many charges of ordinary explosives. But these options were cumbersome, complex and ineffective. In the 1950s, a “Swan” scheme with only two charges was developed, in which the shock wave from them propagates so as to evenly compress the fissile materials in the center.
In CoaDE, developers are forced to use approximate calculations (the real secrets so far), but the characteristic “egg” of a warhead is very recognizable.
The designer allows you to create a warhead with only fissile materials, and enhanced by nuclear fusion. This is done simply - a portion of the mixture of deuterium and tritium is injected into the central cavity of the charge (which is useful also for a bomb only in fission). Unlike real life, where gain is always useful and very convenient for controlling the power of an explosion, in CoaDE in compact charges it can interfere. Also, alas, the game does not have a Teller-Ulam scheme that allows you to create light and compact warheads of tens and hundreds of megatons.
The desire to make the most compact charge makes you look at the history of atomic weapons - how much progress have you achieved there? The smallest was the W54 warhead (27x40 cm, 23 kg of mass, power from 10 tons to kilotons), which they wanted to put on the Davy Crockett nuclear recoilless weapon and use as a nuclear bomb.
An interesting question is the most appropriate TNT equivalent of a warhead. Experiments in the game show that 10 kiloton warheads are very effective - the smaller ones are too weak, and the larger ones become heavy and acquire the bad habit of chain detonation, when an explosion of one rocket undermines / destroys nearby missiles.
Cannons
Powder guns seem too outdated to fight in space, however, they have already managed to go there (and even shoot!), And in the future they may well find their niche.
In real history, the NR-23 aviation automatic gun was installed on the Salyut-3 orbital station, and, when flying in unmanned mode, it was successfully tested. The aimed range of the gun was estimated at 300 meters, so its only task was self-defense from slow-moving satellites or manned US ships.
Firearms are good because the energy needed for the shot is already stored in finished form without the need to power the gun from the reactor. But guns also have a serious problem - to increase the effective firing range, it is necessary to increase the velocity of the projectile, and with chemical explosives it is difficult to make it higher than ~ 2 km / s. The reason is simple - in the ideal case, the projectile needs to be accelerated evenly, and when the powder burns and the projectile moves, the pressure in the barrel behind the projectile changes. They try to fight this, for example, a special artillery powder charge burns from inside to outside through several channels, increasing the burning surface over time and emitting more and more gases, but he still does not keep up with the increase in volume in the barrel behind the projectile.
Guns cannon, canals are perfectly visible, the outer surface is covered with a special non-combustible composition.In real technology, they are trying to increase the speed of the projectile in various ways, for example, by making multi-chamber tools or experimenting with light-gas guns (a speed of 8 km / s is achieved). In CoaDE firearms do not even need to cool the barrel, which is unrealistic, but the inability to accelerate the projectile to high speed limits their use.
Below you can see a typical graph of pressure changes in the barrel as the projectile moves.Railgun (railgun)
If we take two guides, apply a potential difference to them and close them with a conductor, the Ampere force will begin to act on the conductor, accelerating it along the guides. It will turn out to be a railgun, also known as a railgun.
The idea of a gun in which the projectile will be accelerated by electricity, has arisen for a long time, and the first experimental railgun was built in the early 20th century. But all this time, the idea remained in dreams - for a shot, it required the energy of a power station, which you cannot take along the battlefield. Today railguns are being tested and will soon appear on warships, but will remain rare exotic for a long time.
The atmosphere strongly interferes with high-speed projectiles - their energy grows as a square of speed, but the air resistance is like a cube of speed. But in space, atmospheric molecules will not interfere, and the railgun will be one of the best weapons. In the real world, various problems arise such as rail wear, but in CoaDE the railgun is the simplest and most effective design tool. Light projectiles can be accelerated to tens of kilometers per second and literally flood the enemy with their flow, even outside of the calculated target range.
Green - tracer shells, pay attention to the almost flat graph of the acceleration of the projectile, it is a sign of efficiencyGauss Cannon
Another variant of acceleration of the projectile - electromagnetic attraction. The projectile is placed in front of the coil, to which electric current is supplied, the “pulling” projectile into the coil.
In theory, the Gauss gun is capable of providing a greater projectile speed than railgun, but even in CoaDE it is much more difficult to design - the need to understand the effect of the number of turns in a coil, its layers of winding and the thickness of the wire makes the task very difficult. In reality, the military is not interested in Gauss guns, unlike railguns, and the topic is interesting mainly to enthusiasts who assemble quite compact multi-stage units.
The stepped acceleration profile leads to a large mass of the barrel and low final velocityLasers
And, finally, combat lasers, which became in many ways a symbol of war in space. I hasten to disappoint fans - even without interference from the atmosphere, lasers are not a panacea. The fact is that the beam is inevitably scattered due to diffraction, and as the distance increases, the amount of energy falling per square centimeter of the enemy's surface decreases. And where does it, by the way, come from?
A laser is an abbreviation for “amplification of light by stimulated radiation.” A special pump lamp irradiates the working fluid by sending photons to it. In the working body, atoms move to a higher energy level, and then, under the influence of a photon, emit a new (photon) moving in the same direction (coherent), in fact, amplifying light.
In real military technology, lasers have long been used for target designation and distance measurement, but in recent years combat options have also appeared. They have a relatively short range and can only work as an addition to the already existing air defense systems. As for the cosmos, then the laser does not become a super-weapon. Alas, despite the fact that the physical principle itself provides coherent radiation, lasers suffer from diffraction, and the radiation power decreases with distance. Further, the laser requires a lot of energy, and the whole process has a depressing efficiency. The thermal energy of the atomic chain reaction is converted into electrical energy, then into the light of the pump lamp, transferred to the laser's working body and radiated through the optical system. And at each stage, some of the energy is lost, converted into parasitic heat, which must be removed and dissipated.
Bright red is an ellipse with a pumping lamp in the left focus and a working body in the right. The surface of the ellipse is a mirror; a cooler is pumped inside.Useful uncertainty
Which weapon is better? At the moment, none of the options for weapons is totally dominant - you can design a ship that will defeat the existing ones, and then another, which will again win all. The situation is made more interesting by the fact that the game does not impose restrictions on the combination of weapons. You can create, for example, a gun that shoots nuclear warheads. Or the rocket launching drone. Or railgun shooting drones that drop laser drones from a target. In general, rockets are good because they can come close very quickly, and you can send them a lot, overloading any missile defense target. Lasers can pinpoint equipment over long distances, and become very effective anti-aircraft guns with reduced distance to the target. Railguns take up little space, and can flood a target with streams of shells at long distances. And one drone, sent to intercept a group of missiles, can force them to maneuver, depriving the delta-V or simply shooting. Also, there are no perfect ship designs. Someone prefers to reserve knots so that the ship cannot be incapacitated with one hit, someone, on the contrary, constructs a lot of relatively small ships for the same amount of tonnage and money that will survive the loss of part of the group. In general, it is interesting to play.
Armor
Naval warships lost their armor with the appearance of atomic weapons and missiles - no armor could protect them. Then, after the bitter experience of the destruction of ships from relatively weak weapons, armor appeared again, but remains very light. The main defense of modern naval ships is air defense, as well as jamming systems and spurious targets in different ranges. In CoaDE, however, armor is highly demanded - it does not allow to see the inside of a ship, in order to shoot, for example, the reactors or crew compartments, and, moreover, it really protects against enemy weapons. How can you stop the projectile, which flies to you at a speed of 10 km / s? Paradoxically, but quite simply. The physics of collisions at tremendous speeds is such that if two layers of thin armor are placed at a certain distance from each other, the projectile will collapse upon meeting the first layer, and the fragments will not be able to penetrate the second.
On this principle, and built armor in CoaDE. The standard option is a combination of a relatively light metal such as aluminum and composite materials under it. They say that in one of the previous versions between the layers, the airgel worked well (and it should work, airgel catch micrometeorites in real scientific devices), but for some reason now the effect of it is imperceptible. There are some remarks to the limitations of the design of ships in the game (it’s impossible, for example, to air all the space under the armor), damage system (damaged blocks disappear too quickly and do not work as a shield, protecting what is under them), but now it is very interesting and continues to get better - in the December update added the ability to make armor tight and design not only round, but also polygonal ships.
Conclusion
Children of a Dead Earth is a very unusual game, and this is extremely curious. Yes, she has a rather high threshold of entry, but the seriousness of the physical problems solved in a game form is such that you should definitely try to slip her children into high school, she can at least improve their grades in physics.
PS Alas, unlike Orbiter or SpaceEngine, the game is paid, sold on Steam. Also, there is no Russian language, but in the December update they added the ability to add localization files, Russification is waiting for altruistic enthusiasts.