Tower Defense Strategy

In September, the Future Space Station changed a group of people and became busy again.

In addition to improving the personnel space and preparing for the expansion of the gravity simulation area in the future space station in the past six months, the most significant change is the evolution of the assembly work surface.

Previously, the working surface of the future space station was a truss structure with movable steel plates, with an area of ​​only a few hundred square meters.

However, with the increasing frequency of ground launches, countries C, Central China, and R each have a new electromagnetic orbit launch station completed or under construction, and the original working surface seems a bit out of date.

The work face reconstruction plan began with the preparation work of the dry nuclear power cargo team. The work started in May and was completed in mid-August.

It is completely different from the original working surface on the side of the space station.

The new working surface is located directly above the space station (sunward side), and is omnidirectionally opened. In the middle is a newly-added spacesuit cabin connected to the core hall of the space station. There are three elevator structures...It is the canned decompression cabin mentioned several times before. The practical version.

The can decompression chamber itself is designed for survival in emergency situations. The advantage is that it occupies a small area and the time required to exhaust the air is short.

After accumulating enough test experience for each spacecraft and lunar space station, a practical version is available.

The practical version is not a simple can lifting or rotating, but a logistics system.

Take this set installed in the future space station as an example. It has three entrances and exits, a total of nine "cans". After sending people out of the cabin, the cans will enter the queue area, and the computer system will arrange the air pressure for the cans according to the shore row of the day's unloading tasks. Waiting for the next time the astronaut presses the panel.

The reason for not using the five-stage decompression zone that has been proven by the Lunar Space Station is because this is a low-Earth orbit space station after all, and the future personnel capacity will not be too large, and after losing contact with the ground, personnel will be transferred out one after another. , There is not such a high frequency of access requirements.

The working platform spread out around the three elevators of the practical version can is divided into two working surfaces.

One is the backlit working surface, or the original truss and steel plate structure. The height from the ceiling to the floor is six meters, and the total area is about 400 square meters. It is divided into a robotic arm operating area and a personnel operating area.

The robotic arm operating area is equipped with a set of low-flux electromagnetic tracks, responsible for pushing the assembled things out of the working area, and then the robotic arm outside will take over.

The structure of the upper working surface is more luxurious. It is a truss, photovoltaic panel and alumina glass panel structure. This working surface is also called a robotic arm chessboard. There are 100 evenly distributed interfaces on it for a small crawler robotic arm. Exercise and work. When not in use, the robotic arm crawls on the outer edge to help the lower working surface work.

The biggest advantage of the new working face is that the main assembly area avoids direct sunlight and has more room for operation than the previous working face.

In addition to being powered by direct sunlight in space, everything is bad.

Space station assembly rockets and spacecraft have to face ubiquitous cosmic radiation. If they face the sun, they have to withstand the high temperature of Baidu. Many precision instruments and parts cannot withstand such a harsh environment. Therefore, the rockets assembled by the future space station, They are all assembled with a radiation shield in modular assembly.

However, the next step is to build a more powerful earth-moon transportation system, and then red star research and transformation will be involved. The meaningless dead weight of the radiation-proof shell installed inside has become a problem that must be solved.

In addition to the two working planes, the original working plane was dismantled and sent to the Kunpeng Space Station and the Moon Palace. The location was replaced by a set of electromagnetic orbits specially designed for the future space station.

It is not a tunnel type, but more like a practical electromagnetic ejection device on an aircraft carrier, with the hook changed to a detachable fixed ring.

The length is less than two hundred meters, it can give 20 tons of objects, and the extra speed of 300 meters per second is not much but it can save a lot of fuel, mainly to make full use of the energy brought by the Dragon Ball nuclear power system. Once nuclear power is a thing Startup can only reduce output, and it cannot be completely shut down before a set of fuel is burned out, and it is wasted if it is not used.

These are the work done in the last two shifts.

In addition to the daily processing of ground materials, the new shift starting in September has two key businesses.

First, country C sent another new thing to the sky, the laser energy platform verification machine.

It is a component used to cooperate with the low-orbit space-based weapon program. If it can pass the test, it will greatly reduce the cost of low-orbit space-based weapons.

The demonstrator was dropped in an equatorial orbit at an altitude of 5,000 kilometers, and it was a special test machine released from the future space station to cooperate with the test.

The verification machine orbited for about three hours, which was inconsistent with the low-Earth orbit angular velocity. Considering that there are still trace gas particles in the low orbit, the transmission window is about 185 degrees in radians, which means that every 80 minutes will have slightly more than half of the time. Can transmit energy.

The test machine is a shell with a large amount of non-renewable garbage as a counterweight, but it also has a small power system to cooperate with the experiment.

After being pushed out by the electromagnetic system in the reverse direction, it automatically lowers the orbit and brakes with RCS at a position of 350 kilometers.

The RCS single-component thruster system is also obsolete, which is the kind that can fail at any time.

With just such a brake, there are three failures in 24 nozzles. They circled the ground twice. After several interruptions and corrections, they adjusted to the normal near-ground circular orbit, facing the sun.

There is a little difference between the sun in space and the sun on the ground. It does not need to move, and always faces the sun. Of course, the low-Earth orbit will be blocked by planets for half of the time.

After adjusting the direction of the testing machine, verify the action of the machine.

The laser energy platform does not have an RCS system, and uses a combination of pure momentum wheels to achieve attitude changes.

Aim at the target area first, unlock the internal lock, and the momentum wheel module enters the maglev mode.

Next is the low-power sighting, using less than one watt of laser, to search for the target's laser receiving crystal.

In order to avoid accidents when the main laser is irradiated, the laser receiving crystal is designed to be placed outside the testing machine, and the main body is connected with a bracket and related structures and cables.

The crystal is sighted and the feedback signal of the system is received.

The verification machine enters the fine-tuning mode. In the fine-tuning mode, only a small momentum wheel will be locked again, driving the verification machine to move, and the adjustment range is very small. In order to maintain an absolute standstill after adjustment, the process is also very slow.

During the adjustment process, the crystal search system and computer of the verification machine did not stop, and received signals from the receiver again and again.

After 30 minutes of automatic fine-tuning, the sighting is completed.

Energy transfer started!

A laser with a power of one megawatt penetrates the space, hits the laser receiving crystal, is immediately refracted into a circle, diffuses again from the crystal below, throws it on the fake "photovoltaic" board for testing, and observes with another set of measurement system The "photovoltaic" panels receive light and heat conditions.

At first glance, this energy transmission method seems a bit blind, but it is actually helpless.

The existing technology of mankind, let alone a megawatt of laser, can be produced by hundreds of megawatts. The problem is that after the laser power is too large, there is no photovoltaic panel with enough area to turn back into electricity. It is useless. Such a large power is the only thing. The way to use it is to boil water to generate electricity!

When it comes to boiling water, it is an old problem. The greater the power, the heavier the device, what else can be saved? With this weight, wouldn’t it be good to have more batteries?

Therefore, the laser transmission scheme can only use the photovoltaic panels that come with low-orbit space-based weapons to achieve the purpose of energy transmission, and the power cannot be particularly high.

The use of photovoltaic panels has another problem mentioned earlier, the conversion rate.

The best photovoltaic panel for mankind has a conversion rate of 40%. Unfortunately, it has not yet been mass-produced. The extra energy is either reflected or dissipated in the form of heat dissipation by the thermal control system, which is wasted anyway.

Therefore, even if there is a large enough photovoltaic array, the transmission power of one megawatt can only use three or four hundred kilowatts at most. Such power is still not good enough to promote the weapon-grade electromagnetic orbit, and it depends on the battery.

In fact, country C's final near-Earth space-based weapon program may only receive a few kilowatts of power. The specific value will be determined after the experimental results return to the ground.

The one-megawatt laser was scattered and hit the fake photoelectric panel. The heating was very fast, and it melted in less than 20 seconds, and the test was terminated.

Waiting for the heat radiation to cool down naturally, the testing machine uses a telescopic mechanical structure to put the damaged fake photoelectric panels and laser crystals, as well as non-recyclable garbage, into a cabin.

Close the hatch, start the rocket propeller to slow down and return to the atmosphere.

In the future, the space station will be responsible for using the Yinglong-3 spacecraft to capture the verification machine for damage inspection and modify it according to ground instructions.

This is not a big project, and most of the preparatory work has been completed last shift.

The main task of the September shift is to replace the rocket engine.

The problem has dragged on for a while, but the rocket engine needs a lot of ground testing.

The life of the old rocket engine is calculated in seconds. The orbital engine is a little better, but not much better. When it is used repeatedly, a lot of inspection and maintenance work is required for each mission. Each mission requires ground personnel to be careful. planning.

The goal of the new generation of engines is to match the life of the aircraft. Of course, it does not require several hundred hours, but at least it must be able to use it intermittently for dozens of hours.

After a lot of ground work, the future space station has also made some contributions in terms of materials, and the new engine has only recently been finalized.

Someone asked, what else do ordinary engines do if there are droughts?

It's not that Droughts have not yet reached the safety standards for manned vehicles~www.wuxiahere.com~ So once real people are involved, traditional engines are still needed.

The new engine has two models. The shape is not much different from the previous orbital engine, but the heat radiation reflection of the engine and the tail of the spacecraft is one level higher than that of the old model. Relative to the size and weight of the engine, the thrust is slightly smaller than that of the traditional model. a little.

The problem of heat radiation reflection is a key problem that affects the life of the engine and the single ignition time. It mainly depends on the material and surface smoothness. In the use of old-fashioned rockets, it is affected by the rocket launch itself in the atmosphere and the impact on the launch. The actuarial calculation of weight is relatively limited in the degree of mirroring.

Now that it is possible to assemble engines directly in space, most of the weight bottleneck has been solved under the large-scale application of electromagnetic orbital launchers, and the solution of the problem is not a cross-generational change.

Increasing the size and weight under the condition of the same thrust is also a general life extension method. It is similar to a diesel engine. If the strength of cast iron is not enough, it can be thickened and it can always be used.

It is also a helpless move. The material advancement accumulated by the existing zero-gravity processing is not enough to keep the engine's weight unchanged, and the life expectancy will increase.