Tower Defense Strategy

The test flight of the Longmen spacecraft was not smooth.

The first question is that the entrance height of the Longmen is five kilometers lower.

Five kilometers may not seem to be much, but every change in speed consumes non-renewable ΔV. In order to save a little bit, the gantry spacecraft has to go around one and a half more times at the altitude of five kilometers, and use the Homan transfer method to ascend the orbit.

Such a height error is actually normal for spacecraft launches, but it also shows that there are some minor problems in weather and airflow monitoring, and management needs to be strengthened.

The fuel redundancy of the first-stage rocket design is also insufficient, and it seems that this part of the money cannot be saved.

The second question is docking.

The docking consumes 30% more RCS single-component fuel than the lowest expected.

Because the gantry spacecraft is relatively short, it is necessary to test a new single-component thruster. Its characteristic in a vacuum environment is a bit larger than the impulse. It is more sensitive when performing swing adjustments. It swings its head many times and continuously adjusts the swing back to the ground personnel. A misoperation instruction was also issued, causing the gantry to turn on the spot.

The characteristic specific impulse of the first stage of the rocket's main engine is between two and three hundred, and the vacuum specific impulse will be greater than sea level. The upper-level engine has almost no thrust at sea level, but when it comes to a vacuum environment, it is at least 320 upwards. Country C has frequently used engines with a specific impulse of 450 at this time.

Compared with the main engine series, the characteristic specific impulse of the single-component engine used in the RCS system is very small, less than two hundred.

The single-component system rushes to the sky with such a small ratio, and it is suspected of wasting fuel. However, compared with the two-component mode of ordinary combustors and oxidizers, the single-component system has high reliability, good controllability, and can last longer. The continuous propulsion and other advantages give it an irreplaceable advantage in the aerospace system.

Although country C has already exerted its power on the electric propulsion system at this time, the electric propulsion will not be able to rise for a while, and the single-component engine cannot be put down.

This test is a single-element, electric propulsion integrated system. The data collected by the ground test has a maximum specific impact of 280 in the vacuum environment. Because of the tight time and no space flight, the automatic docking with the power system of the spacecraft There are still some flaws in the control program, which is also one of the factors that cause testing problems.

Fortunately, the Longmen spacecraft was already within the visual range of the future space station, and the situation was reported to the ground immediately, and the thrust was shut down in time. Otherwise, if the ground is not detected in time, add another thrust in the same direction as the rotation, and the rotation angular velocity may be too fast. disintegration.

The third question is re-entry.

The Longmen spacecraft provided a batch of food supplies and a small amount of cheap processing materials for the future space station, received the goods to be transported back to the surface, and set off directly.

It was a water-floating reentry, but after entering the atmosphere for the last time, something went wrong when the heat shield needed to be unfolded, and the shield did not open correctly!

It uses an expandable thermal shield that allows the spacecraft to gain extra braking strength when it re-enters the atmosphere. Obviously, this unfolding structure has a slightly higher complexity for a reentry device that has to experience thousands of degrees of high temperature many times.

Fortunately, as a manned lifeboat and reentry ship, the design process of the gantry considered that the heat shield could not be properly deployed, so there was still a normal parachute, but the spacecraft did not hit the ground at high speed.

The expandable thermal shield is actually a traditional problem. In the final analysis, the progress of materials science cannot keep up. There is no suitable high temperature resistant flexible material, or flexible thermal conductive material plus ablative agent, and the expansion structure is made of rigid materials, and the complexity is inevitable. Will improve.

If the reliability of the expandable heat shield can reach 100%, the deceleration umbrella and its container and mechanical structure can be eliminated. For a big guy like the gantry who needs two sets of deceleration umbrellas, hundreds of kilograms of weight can be saved, regardless of Whether to add replenishment or oxygen regeneration powder can further enhance the functionality of the spacecraft, it seems that it is not mature enough now.

The heat shield design team urged sadly, because according to the result of the quarrel in the previous configuration plan, the gantry spacecraft had to be modified after returning to the ground, replaced with a traditional heat shield, and the shell would be slightly modified and changed to a speed brake plan.

The shape is similar to the type of air brake used in the landing of a fighter plane, but there are also differences in the aerospace air brake. It is dangerous to use a hydraulic system when the temperature is too high during reentry. It can only be designed through structural design and adopts a paragraph type mechanical structure. Expand the angle.

The weight of the air brake solution is 40 kilograms heavier than the expandable heat shield, so I didn't win a fight before.

The structure of the speed reducer is simple, and the reliability is definitely higher, but the key consideration of the aerospace system is how high the reliability can be.

If the reliability of opening at least a pair of reverse air brakes can exceed 98%, you can consider throwing away a set of air brakes. The reliability of two sets of four full-opening can reach 99.2% or more. With the help of the adjustment of the re-entry program, it is not necessary. The deceleration parachute and even the parachute can be designed to be more windy, and the size can be reduced a bit, which can still save a hundred kilograms of weight in combination.

Most of the small hurdles that appeared during the flight can be attributed to the fact that the gantry has adopted more new technologies, and the focus is also on the inspection after landing.

The gantry spacecraft is manufactured for reuse in order to further reduce the cost of manned space transportation.

During the reentry, not only the body protected by the heat shield, but also two rail engine rectifier nozzles placed outside the shield are to be tested. This is also one of the reasons why the expandable heat shield won in the early stage.

The engine can withstand a high temperature of two thousand degrees, but when re-entering, the engine nozzle must face the ground. When the heat shield cannot be properly deployed, it will be affected by additional aerodynamic heating due to its shape.

The first thing that was found after landing was to conduct flaw detection on these two engines.

The gantry spacecraft has a slender landing gear structure. This landing gear is responsible for providing a buffer for the spacecraft when the falling speed is between 4 meters per second and 8 meters per second. They play a very good role without letting the nozzle hit the ground. , This also means that the impact speed is low enough, and the dummy inside will definitely not be a problem.

The subsequent flaw detection results are very good, except for the blackened surface, there is no problem with the engine, and it can be used again!

Towed away, repaired and replaced, ready for the next round of testing.

In the next round, the Longmen spacecraft will deliver Homo sapiens robots, and the next round will be used to actually carry people.

The test is completed here. In addition to cooperating with the daily launch, country C has mobilized a batch of communication and monitoring resources to cooperate with country R to conduct the first actual launch experiment of a 4.1-meter caliber transmitter.

Previously, country R had completed the ejection experiment of the fake rocket and its acceleration shell. The real rocket on this round uses ordinary cargo loads. The bears are more vigorous, and they will send 46 tons of load.

Although rocket technology is a legacy of decades ago, fortunately, Daxiong has been poor in these years, and has been trying every means to maintain the operation of aerospace institutions and related production capabilities. After obtaining super-computing power support and partial technical support from country C, Electromagnetization is very smooth.

As a result, I don't know which part of country R has a problem. When the cargo hold was in orbit, it was 500 kilometers away from the future space station.

If you don't perform three to four correction maneuvers, the distance depends on the normal chase, which takes about a week.

After all, it's a big bear, and the accuracy of the work is a little rough, and everyone understands it.

Because the future space station will be assisted by personnel, spacecraft, and various robotic arms, docking is considered the least important element of this launch. It can now be concluded that the electromagnetic orbital launcher of country R can enter the practical stage.

The transmitter of country R can be used, what about the one in Xizhongzhou?

Sorry, I'm still arguing about the location.

There are too many problems in the community mechanism of West China. Especially as an organization trying to realize the integration of West China, many members have veto power.

For example, this time, country F and country G will be built in their own homes. After compromise, the two sides decided to build in the middle of West Central Continent, near the junction of country F, country G and a neutral country. The body is located in country F, only a few minutes from the border. Kilometers, but other countries are greedy and opposed!

The launcher is greedy because it looks like a new type of rocket launcher, but it is a growth point for West Central Continent, where the economy is regressing in the monster era.

The production of parts and components involved in commercial secrets of the rocket is impossible to relocate from various countries, but an assembly plant is definitely needed next to the launcher, and because of the launch frequency advantage of the electromagnetic orbital launcher, one assembly plant is not enough. Just enough!

Each assembly plant is equipped with two hundred engineers, twenty scientists, and hundreds of other types of work. In addition, the launch control center also has nearly a thousand people. This launch base has thousands of resident high-end talents. If the family members are moved to Nearby, it can directly form a city of 20,000 people.

It’s strange for people in country C. Shouldn’t it be called a small town with 20,000 people?

People in Xizhongzhou have their own feelings here, not to mention 20,000 people, 5,000 people can be called a city.

A city composed of launcher-related staff and their family members will naturally attract a group of financial management, insurance, luxury goods and other service industries and personnel to move in because of the huge proportion of top talents.

The temporary team that enters the launch site with the load of various countries may also need a commercial hotel. Although these people do not live regularly, the particularity of the rocket load determines that a team must stay at the launch center for at least one month, which may last more than half a year, and when the launch center is fully loaded, it may be thousands of people.

It can be expected that as long as the infrastructure facilities can keep up, the tax revenue of such a new aerospace city may be as high as that of an old city with a population of 300 to 500,000.

Assuming that some non-secret parts are to be produced nearby, this new city can even become a “medium-sized” city with a permanent population of more than 100,000 in just a few years.

Economic recession requires increased spending on fighting monsters. In this environment, whoever is not greedy will surely become a source of growth.

The result is always noisy and no results.

At this time, the rocket entity test firing of country R was on the news, giving the countries of West Central Continent a blow.

Xizhongzhou and Country R have been rivals for hundreds of years. They have all launched, and we are still arguing.

There is no need for officials to self-reflection, and a large number of local media directly spray.

As soon as the public opinion came up, the efficiency was fast. It only took a few days to determine the position. It was still the point that the F and G countries discussed before. After all, these two are the bosses of Xizhongzhou's money, otherwise many of the wastes would have gone bankrupt and liquidated.

When the construction bidding came, there were problems again.

Because following the steps of country A and demonizing country C for decades, UU reading www.uukanshu.com objectively said that it was quite successful. Therefore, the officials in all parts of West Central Continent are very taboo to take care of the business of country C. Favor one's own people.

As we all know, country C easily won the title of infrastructure madman with its huge industrial volume. Because of the scale effect, it is fast and cheap to build things, and because infrastructure belongs to the category with a relatively low upper limit in various disciplines, the quality has not fallen. .

With their own people in Xizhongzhou, it may be difficult to receive a single order for this kind of business in a few years. The companies tacitly go to death, and the price is four times that of the C country construction company.

On the one hand, the manpower in West Central Continent is indeed more expensive. There is a lax tradition left by the luxurious life of the colonial masters after the world searched for wealth. The work efficiency is not good, and it takes several times the labor cost to complete the same amount of work.

On the other hand, the most expensive superconductor coil in the transmitter body has to be ordered from country C after design (consumption is given a quota). Others use C currency to quote and EU currency to quote. The figures given are similar, but the cost is turned around. rise.

Counting these things, the boss wants to make more money at this price.

Xizhongzhou wanted to re-enhance its own physical industry through the monster crisis, so even if it was disgusting, it still handed over the project to the local company.