Tower Defense Strategy

Time quickly jumped to March.

The Northern Star spacecraft of country R went up to the sky a few days in advance and completed automatic docking with the future space station. After that, through automatic and manual double security checks, a small bug in the fire alarm when the door was opened quickly was caught and dealt with.

On March 9, the first crew of the lunar mission arrived at the space station on a 3.35-meter-caliber disposable spacecraft, and the Northern Star entered the mission preparation period.

On March 11, the dragon raised its head. Everything is suitable. The timing of the earth-moon transfer orbit corresponding to the orbital angle of the future space station is just right.

Leave you!

The Northern Star leaves the space station and performs a reverse RCS acceleration, quickly moving away from the space station.

One minute later, it ignites and the engine burns for 150 seconds, putting the spacecraft into the Earth-Moon transfer orbit.

After eighteen hours of flying, the spacecraft was captured by the moon.

Unlike the automatic landing plan, the Northern Star still uses the traditional landing strategy for safety reasons.

Its transfer orbit will fly over a hundred kilometers above the moon's surface, and perform a short reverse plus line advancing at the near point. The closed orbit is circular, and the orbit passes over the polar base.

This step is actually the same as the first-stage deceleration of directly "smashing" the last lunar watch, except that it will turn into an orbit around the moon after deceleration, and it will not hit the ground.

Flying method is more fuel-intensive than "smashing" up, because it is difficult to directly enter the polar orbit through the control of orbit accuracy without smashing up. The first change of orbit requires additional normal or anti-normal thrust correction.

The advantage is that there is a buffer of the orbit time, the data transmitted back to the surface through the spacecraft's own sensors, and some tasks are fine-tuned, which can effectively increase the landing safety.

While flying around the moon, it coordinated with the surface. A few hours later, when it was hundreds of kilometers away from the polar region, the spacecraft started its engine again and performed a short reverse thrust for a few seconds.

At this time, the speed is not enough to continue orbiting, and under the influence of the moon's gravity, it starts to accelerate slowly towards the ground.

The latter is the same as the automatic landing, through a two-stage deceleration, after the first stage, the cargo box is dropped, and the second stage realizes the smooth landing of the spacecraft.

After fine-tuning during the orbiting phase, the landing precision was very high, and the landing point of the Northern Star was only two hundred meters from the base.

In fact, the existing experience and computing power can be more accurate if there is no atmospheric interference, but it is not necessary. Lunar soil is a very dangerous substance to the equipment, and dust may cause some equipment to work directly in a vacuum environment. In the event of malfunction or even damage, it is good for both parties to keep a distance during landing before the professional apron is established.

The crew is ready, the North Star decompresses the entire ship, and the hatch opens. It seems that a new era has arrived.

The four crew members were two men and two women.

In country C, one man and one woman are real husbands and wives. Both of them are ruthless men who obtained Ph.D. degrees before the age of 28. They belonged to the human biology and plant hybrid breeding system. Among them, the man had a good relationship with the woman when he was studying for a Ph.D. He also took another degree in plant genetics, and will assist his wife in work in the early stage. They were selected together with the muscular woman Bai Qing, just because of personal factors such as poor physical conditions and personal relationships between men and women, the previous rounds of space station missions did not take place.

Another male from country C is a decent astronaut and entered the astronaut system by competition from first-line air force pilots.

By the way, country C refers to mission personnel in the solar system as astronauts, and astronauts outside the solar system, so at this stage it is called the space agency, unlike country A, which is called the space agency. Because there is no difference in most of the languages ​​of Tuqiu, they are collectively called astronauts.

The last one is a female astronaut from country R, ​​two words, beautiful!

She has light blonde hair, light green eyes, a tall and straight nose, fair skin, long legs, and her height is almost 1.8 meters.

Just as the long-legged men in country C have been handed over to the country, the beautiful women in country R who are affiliated to official institutions can easily remind people of a terrible profession, swallows.

This is a type of agent who has overwhelmed countless bosses in West Central Continent and was active in the era of the R alliance. The corresponding male agent is called the crow.

Regardless of whether it is or not, anyway, the beauty of R country, who is proficient in six languages ​​and has two degrees in medicine, passed the psychological, physical, and accident response written tests. Country C has no reason to reject Country R's recommendation.

This group of people is a bit different from the previous plan. They are not all traditional astronauts. The problem lies with Xiong Mei.

The recommended list given by country R this time is one man and two women. The man is too handsome and does not look like a serious astronaut. It seems that there is no difference between choosing one of the three. But after choosing Xiong Mei, it would be inappropriate to get three more male astronauts here. There are also female traditional astronauts. Now one of them is in the Kunpeng space station, and the other is going to the future space station to change shifts in the next round.

As a result, the couple was selected, and the related base development plan was slightly adjusted-planting more food.

Leaving the Northern Star, the couple first carried a few small boxes to the base for supplies. The pilot and sister Xiong had another job, putting the cables.

The North Star will be placed here as an energy device, and of course it can also be used for rescue or retreat when necessary.

The cable is specially made, and there are two sets of systems, one is ordinary aluminum core wire and the other is superconducting wire. Through a specially designed cable connector, the superconducting mode will be activated for a period of time after the outside temperature drops to zero.

In addition, there is an air pipe in it to help dissipate heat when the aluminum core wire is working, and it can also be connected to the cooling system to start the superconducting mode in advance.

It is not energy-efficient to design the line so complicated, because it is changed to a pure superconducting wire and a cooling tube, and the weight saved is transported by a solar panel, and the saved energy can be retrieved.

The new line is more of a new standard for development and use with the moon.

There are many places on the moon where the underground temperature is below zero, and the White Magic Guide can directly activate the superconducting mode. However, as the development progresses, the vacuum itself does not conduct heat, and temperature rises will inevitably occur in some areas. If it is a mine, a cable There is also the possibility of being damaged by factors such as falling rocks.

This slightly more complicated wiring system is to prevent the power from being cut off suddenly and completely under certain circumstances.

When the current is too large, the aluminum core wire with insufficient diameter is easy to melt, but at least one time can be obtained to stop the work ahead. In particular, the moon's gravity is low and there is no air. The difficulty of work is several times higher than that in the earth ball mine. It is safer and faster to perform on-site repair and disposal with a certain amount of power than using emergency lights and handheld devices.

The new type of wire fully considers the transportation cost and does not hesitate to increase the production cost. The weight per meter is 0.23 kg per meter, and only 230 kg per kilometer. Due to the difficulty of technology and production, the price can be more than ten kilometers. Ten kilovolt cable.

There are ten kilometers of wire in the box just dropped, and the connector is in another small box of the Northern Star.

The effect is also very reliable. Superconducting mode is not mentioned. In emergency mode, it can work stably with 120A current. It can be changed to damage mode through the electronic control system (air-conditioning must be ventilated, short-circuit insurance must be skipped, and aging accelerated), 500A can be loaded, and Can withstand 1500A instantaneous current. Such current load capacity, in the moon of one-sixth gravity, is sufficient to support most types of equipment failures.

Since the Northern Star is an electric power unit, of course it has specially prepared for it.

In addition to its own solar panel heating battery, it has a total power generation capacity of about 1500 watts in the polar regions. In addition, there is a series of new cable interfaces on both sides of the fuselage, which can be connected to a stack of solar arrays.

…Yes, the biggest part of the Northern Star’s own weight is a set of electrical control system, which is very thoughtful in design and can be removed when the base conditions are suitable. After dismantling, only the lower half remains between the engine and the main cabin, which will be very ugly.

The pilot and sister Xiong don't care about the external array, they only load the cable.

Two hundred meters, because of the low gravity and the heavy space suit, it was difficult to walk. It took half an hour to get it done.

After all four of them arrived at the base, they had something to eat first.

Eating in a gravity-free environment may seem interesting to outsiders~www.wuxiamtl.com~, but more experience is a torture. Astronauts need to receive special training to find pleasure in it, so as not to be furious.

Although the gravity of the moon surface is lower, it is also gravity. In this environment, you can drink porridge, drink liquid drinks and water in an open cup, which is definitely more enjoyable than drinking with a tube.

While having a meal to celebrate the initial success of the mission, we had a short meeting with the ground mission center. Two Homo sapiens robots went to the Northern Star and used several sets of solar materials to lay the array. The remaining Homo sapiens are also divided into several groups to recover the airdrop boxes.

In addition to the two boxes dropped by the Northern Star, they set off later, but landed on the surface by "smashing" them. The Application One, which landed three hours earlier, also brought three boxes of cargo.

The power of the equipment on the robot is low, and the moon does not have a sound GPS system. It relies solely on visual observation, calculation and radar. Xiong Mei is loaded on the base to assist the Homo sapiens robot, which can improve the recovery efficiency a bit.

The couple stayed at the base to check the planting results of the Homo sapiens robot.

The pilot went to the tunnel that the robot opened to the ice to conduct a site survey.