Construction started after the New Year, and Muyang began to inspect the progress of the satellite project.

Come to the lab and see them testing the performance of the battery.

Batteries are installed on the satellite, which mainly supply power to the communication system.

The solar array absorbs energy mainly for battery charging.

There are generally two types of satellite batteries, one is nickel-cadmium battery and the other is nickel-hydrogen battery.

At the same weight, the nickel-hydrogen power reserve is 30% more than that of nickel-cadmium batteries, which is lighter than nickel-cadmium batteries and has a longer service life. The disadvantage is that the price is much more expensive than nickel-cadmium batteries and its performance is worse than lithium batteries.

Ni-hydrogen batteries do not contain "hydrogen", but metal hydrides such as potassium hydroxide (KOH). Like nickel-cadmium and lithium batteries are all alkaline batteries, unlike lead-acid batteries.

Nickel-cadmium batteries have dominated satellite applications over the past three decades.

NiMH batteries are used relatively late, and self-discharge is a problem.

Xinghai Group’s satellite uses nickel-hydrogen batteries, which are assisted by the company’s battery project team. There are also such batteries sold on the market, such as No. 5 and No. 7 batteries, which are not expensive, but they do not meet the requirements of Xinghai Group’s satellite batteries.

Satellite batteries require a long life, at least ten years, and more than ten thousand charges. Generally, civilian nickel-hydrogen batteries do not meet this requirement.

After all, it is impossible to replace the battery for a satellite. If the battery is broken, the lifespan of the satellite will reach its end.

If it is an Interstellar Travel Discovery satellite, it requires a longer life span.

NiMH batteries will also self-discharge. Today, they may have a capacity of 10Ah. It may have been a while since they only have a capacity of 9Ah. This will also occur on other types of batteries. If they are not used for a long time, they suddenly find that the power has decreased. This is what it means.

This problem may be a fatal problem for projects that require long storage.

Mu Yang observed for a while and saw Lu Ding, the R&D manager of the project team, and asked casually: "Dr. Lu, how much capacity is the nickel-hydrogen battery pack you use?"

Lu Ding replied respectfully: "Chairman, according to the design requirements, 200Ah ampere hours."

[1Ah=1000mAh, 200Ah is approximately equal to the capacity of seventy or eighty mobile phone batteries; if the discharge current is 1A, the discharge time can be 200 hours]

Mu Yang converted it and said that if the output voltage is 12V, then a battery like 1AH, W=12*1*3600/(6*1000000)=012 kWh.

For a battery pack such as 200AH, W=12*200*3600/(6*10000000)=4 kWh of electricity=2400WH.

The power required for a communication system is between 500W and 6000W, which has a lot to do with the satellite quality. If it is a high-power communication system, if it is a 500kg satellite payload, 200Ah is enough.

The original design weight of Xingdou-1 is about 278 kilograms. According to conventional conditions, the battery pack capacity is definitely enough.

Stardou-1 is different from general satellites. It not only communicates, but also has remote sensing and reconnaissance functions. It is a combination of optical satellites and radar satellites. It is the world's first, so it requires a larger battery capacity.

In fact, such a nickel-hydrogen battery pack is not heavy, about one kilogram, and with other accessories only two or three kilograms.

On the contrary, solar cell array occupies a relatively large weight, with a specific power of between 10-50W/kg. It belongs to a single crystal silicon solar panel with a conversion efficiency of about 24%. From this data, it can be seen that its charging efficiency is very low.

If the battery pack has 20 kilograms, it will take about 30 hours to fill it with 200Ah, and the efficiency will be slower.

It doesn't matter if the capacity of nickel-hydrogen batteries is a little larger. It only needs to ensure that there is enough power to supply power when the sunlight intensity is weak during the sunlight point. The main thing is to look at the charging power of the solar cell array. If the solar panel area is small and the power is small, it cannot meet the usage requirements.

Mu Yang emphasized: "There are many technologies to solve for satellite projects. When the project was established, I reminded that Rocket Star One has strong carrying capacity and there is no need for satellites to pursue lighter capacity.

The higher the precision, the easier it is to break, and the higher the cost. You should pay attention to this point.

On the other hand, we plan not to launch a few Stardou-1 satellites, but to plan 20,000.

According to the theory, our launch cost is not high. Even if the launch cost of the Starry Sky One rocket launches once to LEO is 10 million yuan, the average load cost per ton is only a few thousand yuan.

If the manufacturing cost of satellites can be reduced, if each satellite saves 500,000 yuan or 20,000 satellites, we can save 10 billion yuan."

The manufacturing cost of Muske's starlink satellite is about 500,000 US dollars. The satellite is flat, with a size of 2m, a 9-type weighs 227 kilograms, and an upgraded 0-type weighs 260 kilograms, which is a small satellite.

Xingdou-1 of Xinghai Group is also a small satellite. It not only has communication functions, but also has reconnaissance and other functions. It has stronger performance and more functions. If it adopts a lightweight design, the design and manufacturing cost will reach 3 million yuan per cable.

The world's first Stardou-1 satellite function will not be disclosed, but the payload capability of the Stardou-1 rocket cannot be concealed and will definitely shock the world.

It was also quickly speculated that Xinghai Group used an extraordinary rocket engine and had an abnormal thrust.

If you do a miracle with great force, you can fly even if you have a brick.

What you play is different.

Lu Ding said: "Chairman, then our previous design weight was 278 kilograms. If we follow the Stark Sky One's carrying capacity, there is no need to use lightweight satellites. It's okay to weigh more than 300 kilograms, or it's okay to heavier, so we can save a lot of money."

"The 278 kg weight design requirement I gave before was indeed unreasonable, and this is my problem.

I see that you have optimized a lot of the design optimization solutions you submitted, but you are still a little conservative.

You are right. In fact, it’s okay to weigh 100 kilograms if Xingdou 1 weighs 100 kilograms. As long as the quality is stable and you are not afraid of collisions, even if the final design weight reaches 400 kilograms.

But our single manufacturing cost can save hundreds of thousands or millions, while the launch cost is only more than ten thousand yuan, which is worth it." Mu Yang replied, "Let's do it this way, call the core personnel of the project team in the afternoon, we will re-examine the design concept, I will review it and confirm it."

If the satellite is heavy, the power requirements will be higher.

The design drawings given by the system are also correct, and the structure is more compact, but the system does not consider the manufacturing cost and the load problem of Starry Sky One.

The system is dead, and people live.

The structure may not be modified, but some expensive materials can be replaced by cheap and reliable ones. As long as the performance and function are not affected, the precision of the parts can be reduced by one or two levels, which can save a lot of costs.

At 2 pm, Muyang and the researchers from the satellite project team held a design meeting to re-examine the design issues of Stardou-1.

After three hours of discussion, a new optimization plan was released.

This is not a new design, it is just a replacement for valuable parts and materials, otherwise it will not be settled in two or three hours.

The final solution is to reduce the manufacturing difficulty without affecting the function, while increasing the structural strength. The final theoretical weight reaches 350 kg, and it is estimated that the manufacturing cost of each satellite can be reduced by one million yuan.

Of course, the increase in weight also means that more fuel reserves are needed to adjust the satellite attitude when dealing with emergencies.

Although some of the previous work done after Xingdou-1 was in vain after optimization, the development difficulty was reduced and the overall process did not change.

At the meeting, Mu Yang criticized himself and did not organize the meeting in time to set the general direction. He also hoped that everyone would find problems and dare to refute them and not make a single act.

Muyang and the scientific researchers of the project team are looking forward to the successful development of Xingdou-1, with global WIFI, high-definition resolution.

Through the Star Network, you can view global scenery and explore the mysterious areas of the earth without going out.

However, there are many problems that Xingdou 1 needs to solve. The scientific researchers of the project team encountered many problems, and some problems even Mu Yang had a headache.

Having technical data is one thing, and whether it can be developed is another thing.

Brain: "I can do it!"

Hand: "No, you won't!"

In fact, this is the reason.

Muyang inspected the battery project team and then inspected other scientific research teams of the satellite project.

The progress is still good. It is estimated that samples can be produced in May, debugged in June, and large-scale assembly and put into use with Starry Sky One in July and August, and it can also catch up with the rocket to launch LEO.

From 2008 to 2016, the past eight years of waiting has finally come to this point this year.

Aerospace development is not fast, but it is laid well, which is different from others. Xinghai Group is about to ignore many complex technologies such as climate change, high payloads, and stable recovery of rockets. Each one is the world's first.

Choose a good weather before launching the rocket?

NO!

Only a dozen tons of LEO launched?

That certainly won't work!

Rockets recycling?

Well, this is a reference to Muske, and it is not a first-in-class.

The problem is that SpaceX's space company hasn't really done it either.

According to history, the first successful recovery of the Spacex rocket was on December 22, 2015, until April 8, 2016, SpaceX successfully recovered the Falcon 9 rocket for the first time.

Now that Mu Yang is tossing, I don’t know how long it has been delayed, but it is definitely under development, it depends on who will implement it first.

Therefore, Mu Yang said that the rocket recycling technology was first created by Xinghai Group, so he would not blush!

Besides, my rocket recycling technology is more advanced than Muske’s!

...

A few days later,

February 22, 2016 is the Lantern Festival.

Muske's space exploration company SpaceX has announced plans for satellite Internet services.

SpaceX plans to launch about 20,000 communications satellites into orbit and work will begin in 2021.

This project is named "Starlink".

The project outlines more details about the Starlink project, including the will provide telephone services, voice call emergency backup services, and the participation of Z House Lifeline program to provide cheaper telecommunications services for low-income earners.

The 4408 satellites in the first phase operate in orbit 550 kilometers, mainly using the Ku and Ka frequency bands, a single-star communication capacity of 20Gbps, and the data throughput of the entire system is 100Tbps.

The 7518 satellites in the second period operate in orbit 340 kilometers, and the V-band was added to the Ku and Ka frequency bands in the first period.

The 30,000 satellites in the third period added the E-band based on the Ku, Ka, and V bands, and the available bandwidth increased by 3 times and enhanced the system capacity.

After Muske made this announcement, he was very proud: Take the lead and become king first!

It's not my fault!
To be continued...