For space launch missions, every gram of material needs to be carefully calculated.
After all, every additional gram of weight increases the cost.
Even for the Hongyan rocket, which has a LEO orbital carrying capacity of 26 tons, saving weight is necessary.
After all, the cost per kilogram is also about 1,750 yuan. Although the cost is not very high, as satellite developers who are used to living a hard life, every gram of weight is carefully calculated.
Even being just a few grams overweight is unforgivable.
And now, the communication satellite developed by One Hundred and One Satellite Research Institute is fifty 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 101 Satellite Research Institute weighs 720 kilograms!
"Dean Zhang, this is already the limit of what we can achieve technically!"
Zhong Zixin, the director of the 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.
The two people were relatively happy after learning about this. After all, it was pretty good to be able to complete the development of the satellite in less than a year.
Therefore, the two of them did not have high expectations for the performance of the satellite. After all, they were not ignorant of the current domestic technical level.
But after seeing this satellite that was almost 10% overweight, the two of them were still a little surprised.
After all, the design life of this communication satellite is not long, and the orbital altitude is relatively low. When formulating the design parameters, its quality has been designed to be quite high.
Of course, this is only compared to satellites in the same orbit. As for those high-orbit satellites that work daily 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 setting the parameters before, your weight is too exaggerated!"
"And when we made it before, didn't we already relax the weight by 40% for you?"
"Why are you so overweight?"
Chen Zhongyan frowned and looked at the satellite prototype in front of him while questioning.
Although Chen Zhongyan had thought about the possibility of being overweight at the beginning of the project, he did not expect that he might be so much 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, those high-power antennas are somewhat overweight!"
"And the communication equipment is also very heavy. This is the latest achievement of the Communications Research Institute!"
Zhong Zixin was also very helpless. Being able to achieve this level was actually the result of all the scientific researchers at the 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 preliminary networking work.
The satellite communication network that has not yet been completed is mainly responsible for areas with relatively dense users such as East and South China.
Of course, at this time, there were actually no mobile phone users nationwide.
As of the end of 1997, there were only 13 million mobile phone users.
Even if 40 satellites are used to serve 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.
Based on the current user usage time period analysis, even during the peak usage time, the number of simultaneous 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 was designed to be 400,000 households.
This number of users is actually very difficult to achieve with current communication technology.
In order to increase the design capacity of communication satellites to 400,000 simultaneous access users, the Communications Research Institute has no better method and can only meet the design requirements through strengthening and enlarging methods.
"There is nothing you can do here. Can you continue to lose weight?"
Zhang Xingyang circled around the communication satellite, which didn't look very big but had several tall and thick antennas. After a few turns, he asked Zhong Zixin.
Weight reduction is a must. During the initial planning, the intended weight of the satellite was actually designed to be about 300 kilograms.
Even after the satellite's weight was lent again and again, it almost doubled to 650 kilograms.
"We are currently doing weight loss work, but judging from the current situation."
"Unless the Communications Research Institute makes relatively big progress in communications equipment manufacturers."
"Otherwise, if you want to rely on us to make a fuss about other parts of the satellite, the possibility of significant weight reduction is not very high!"
As the person in charge of the entire satellite project, Zhong Zixin also wants to reduce the weight of the satellite, but the work required here cannot be accomplished 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 about the time issue and quickly rejected Zhong Zixin's idea of delaying the satellite launch time.
"In terms of rockets, Dean Zhang and the others have been prepared for a long time and have been waiting for your satellite!"
"No matter what, even if it is overweight, we must complete the launch of the first batch of communication satellites before June!"
It's not without reason that Chen Zhongyan is so anxious. In fact, it is running in space like this and plans to use satellites for international communications in the future.
It is necessary to apply for an orbit from the International Communications Union. If the satellite launch cannot be completed before June, the communication satellite will enter the predetermined orbit.
Then the track originally applied for will be automatically invalidated. If you want to use it, you need to apply again.
Here, several months may have passed by going back and forth.
Then the country's project planning for the entire satellite communication network will all be postponed.
Even Chen Zhongyan cannot bear such a huge responsibility.
"If it doesn't work, then we will have to find a way to launch this big guy up regardless of weight."
Zhang Xingyang said helplessly.
In fact, there was a reason for the initial weight of 650 kilograms, so that all forty satellites built in the first phase could be launched into space at once within the carrying capacity of one Hongyan rocket.
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 thirty satellites in the first batch, and the second batch of satellites can actually use second-hand Hongyan rockets."
Although the Hongyan rocket was recycled, there was no actual launch mission of the second-hand rocket.
But Zhang Xingyang is still confident that he can complete the mission of the Hongyan Rocket that he completed by himself!
(End of chapter)
