A big country of aerospace with black technology

For space launch missions, every gram of material needs to be carefully calculated.

After all, for every extra gram of weight, the cost will increase.

Even for the Hongyan rocket, which can carry up to 26 tons in LEO orbit, saving weight is necessary.

After all, the cost per kilogram is about 1,750 yuan. Although the cost is not very high, as a satellite developer who is used to hard life and carefully calculates every gram of weight.

Even being just a few grams overweight is unforgivable.

But now, the communication satellite developed by 101 Satellite Research Institute is 50 kilograms overweight!

According to the pre-established communication satellite parameter table, the weight of the low-orbit communication satellite should be 670 kilograms.

And now the first-generation experimental model produced by the 101 Satellite Research Institute weighs 720 kilograms!

"Dean Zhang, this is already the limit of what we can do technically!"

Zhong Zixin, the director of 101 Satellite Research Institute, said to Chen Zhongyan and Zhang Xingyang.

Three days ago, Zhong Zixin, who assisted in the research of communication satellites, informed Zhang Xingyang and Chen Zhongyan that they had now made the first prototype satellite.

Originally, the two of them were quite happy after learning about this incident. After all, in less than a year, it was considered pretty good to be able to complete the development of the satellite.

Therefore, the two of them did not have too much expectation for the performance of the satellite. After all, they are not ignorant of the current domestic technical level.

But after seeing this satellite that was nearly 10% overweight with their own eyes, the two of them were still a little surprised.

After all, the design life of this communication satellite is not long, and the orbit altitude is relatively low. When formulating the design parameters, its quality has been designed to be quite high.

Of course, this is only relative to satellites in the same orbit. As for those high-orbit satellites that work in geostationary orbit and weigh more than three tons, they are still incomparable.

"Although we had foreseen that the weight of the satellite would be relatively high when we formulated the parameters before, your weight is too exaggerated!"

"And when we made it before, didn't we already relax 40% of the weight for you?"

"Why are you so overweight!"

Chen Zhongyan frowned and looked at the satellite prototype in front of him, asking.

Although at the beginning of the project, Chen Zhongyan had thought that he might be overweight, but he never thought that it would be possible to be so overweight.

"The problem here is more complicated. Although the weight in other aspects has been reduced due to the design life, but because the number of access users must be satisfied at the same time, the high-power antennas are somewhat overweight!"

"And the communication equipment in it is also overweight, and this is the latest achievement of the Communication Research Institute!"

Zhong Zixin was also very helpless. Being able to achieve such a level was actually the result of all the scientific researchers at 101 Satellite Research Institute working overtime!

The goal of the first phase of the construction project is to launch forty low-orbit communication satellites and complete the initial networking work.

The satellite communication network that has not yet been built is mainly responsible for areas with relatively dense users such as East China and South China.

Of course, at this time, there are actually no mobile phone users nationwide.

As of the end of 1997, there were only 13 million mobile phone users.

Even if forty satellites are responsible for mobile phone users nationwide, each satellite is actually responsible for less than 350,000 users.

Moreover, it is actually impossible for these 350,000 users to use communication services at the same time.

According to the analysis of the current user usage time period, even at the peak usage time, the number of concurrent users will not exceed 200,000.

Of course, in order to have some margin to prepare for some emergencies, when formulating the design parameters, the peak number of users is designed to be 400,000.

This number of users is actually difficult to achieve for current communication technologies.

In order to achieve a design capacity of 400,000 users for simultaneous access to communication satellites, the Institute of Communications has no better way, and can only meet the design requirements by strengthening and enlarging.

"There is no way here, can you continue to lose weight?"

Zhang Xingyang circled around the communication satellites that didn't look very big, but had a few tall and thick antennas, and after a few laps, he asked Zhong Zixin.

Weight reduction must be carried out. When the initial planning was carried out, the predetermined weight of the satellite was actually designed to be about 300 kilograms.

Even after the repayment of the weight of the satellite again and again, it almost more than doubled to 650 kilograms.

"We are currently doing weight loss work, but judging from the current situation."

"Unless the Institute of Communications has made relatively great progress in communication equipment vendors."

"Otherwise, if you want to rely on us to make a fuss about other parts of the satellite, the possibility of a large weight loss is not very great!"

As the person in charge of the entire satellite project, Zhong Zixin also wanted to reduce the weight of the satellite, but the work that needs to be done here cannot be achieved by the Satellite Research Institute alone.

"The most important thing is that if we spend a lot of effort to reduce weight, the development time of the satellite may be delayed for a while."

"This won't work, the satellite must be launched before June!"

As the overall person in charge of the entire low-orbit satellite communication network project, Chen Zhongyan heard the timing problem, and quickly refuted Zhong Zixin's idea of ​​delaying the satellite launch time.

"As for the rocket, Dean Zhang and the others have already made preparations and have been waiting for your satellite!"

"In any case, even if it is overweight, the first batch of communication satellite launches must be completed before June!"

It is not without reason that Chen Zhongyan is so anxious. In fact, it is operating in space like this, planning satellites that may be used for international communication work in the future.

It is necessary to apply for the orbit to the International Telecommunication Union. If the launch of the satellite cannot be completed before June, the communication satellite will enter the predetermined orbit.

Then the originally applied track will be automatically invalidated, and if you want to use it, you need to apply again.

Here, back and forth, maybe several months have passed.

Then the country's project planning for the entire satellite communication network must be postponed accordingly.

Even Chen Zhongyan couldn't bear such a heavy responsibility.

"If it doesn't work, then we have to find a way to launch this big guy up regardless of the weight."

Zhang Xingyang said helplessly.

In fact, there was a reason why the initial weight of 650 kilograms was set, so that within the carrying capacity of a Hongyan rocket, all the forty satellites built in the first phase could be launched into space at one time.

Now that the weight has increased by 50 kilograms, it must be divided into two launch missions to complete the launch of the first phase of the satellite system.

"We can launch 30 satellites in the first batch, and the second batch of satellites can actually use second-hand Hongyan rockets."

Although the Hongyan rocket was recovered, it has not carried out the actual launch mission of the second-hand rocket.

But Zhang Xingyang still has confidence in the Hongyan Rocket that he has completed by himself, and believes that he can successfully complete the task!