If it is to simply send payloads such as satellites or spacecrafts to different orbits, this general launch vehicle can do it.
But if you want to send six, seven, a dozen, or even dozens of satellites to different orbits at the same time, you need an upper stage.
To put it bluntly, it is also a first-stage rocket, but compared to ordinary rocket bodies, it is more flexible and has flexible orbit-changing capabilities. Moreover, its engine can be ignited multiple times, can operate in orbit for a long time, and has strong space transportation capabilities.
The reason why Wu Hao and others develop upper-stage technology is to improve the rocket's carrying capacity, especially in deep space and different orbits.
Of course, this is only one reason. On the other hand, they also hope to develop multi-star technology with one stone.
The one-shot multi-star technology here is based on the original technology, and Wu Hao and the others have also made relevant improvements and optimizations to make its performance even better.
First of all, in terms of quantity, it is different from the current one-rocket multi-satellite technology of many countries, which can send two, three, or four or five satellites into the sky. Wu Hao and the others hope to use this technology to send a dozen or even dozens of satellites into space.
Secondly, in orbit, Wu Hao hopes that this upper stage can send the dozen or even dozens of satellites it carries to different orbits.
At present, the one-rocket multi-satellite technology has developed very rapidly. Companies from various countries have experimented with or have used this technology, and have successfully launched dozens or dozens of satellites into space.
For example, the Starlink project promoted by Musk has sent 60 satellites into space at one time, which can be said to be very impressive.
However, these one-shot, multiple-satellite technologies can only send these satellites to the same orbit. In other words, after the launch vehicle sends multiple satellites to a predetermined orbit, these satellites are released one after another.
However, there is a problem, that is, the trajectory of the rocket releasing or throwing the satellite is an upward curve. But if you look down from the top or look up from the bottom, this curve will become a straight line. In other words, they are still on the same orbit, but at different altitudes.
In this way, it seems to solve the problem of multiple satellites crowded in the same orbit.
But this is only temporary. Except for the geostationary satellites on the equator, all other satellites will gradually reduce their altitude due to fuel consumption during operation.
The performance differences between satellites are also different, and the descent times and speeds of these satellites are also different, so there is a great risk.
Falling satellites may affect the operational safety of earth-orbiting satellites, causing collisions or even causing a series of chain reactions.
For example, in the Starlink project, which has been relatively popular in recent years, Musk used Falcon rockets to launch 60 satellites at once.
But these sixty satellites form a chain of pearls, which also means that they are all in the same orbit. So on a clear night, we will often see a string of satellites passing by in the sky.
What Wu Hao and the others want is not this long string of pearls, but the ability to send more than ten satellites to different orbits.
It's really like a space bus, sending these satellites to their intended destinations.
Therefore, this technology is still relatively difficult, no less difficult than a spacecraft. To achieve precise control of the upper stage, only in this way can each satellite be sent to its different accurate orbits.
At present, in the field of satellite technology, countries and companies no longer simply pursue weight and volume, but are increasingly focusing on some micro-satellites.
Compared with ordinary large and medium-sized satellites, microsatellites have unique advantages. First of all, its biggest advantage is cost. The cost of microsatellites is very low, and the cost of one satellite may even be the price of a smartphone.
For example, many university student research teams have developed many mobile phone satellites. In fact, the theme of mobile phone satellite is mobile phones. Relying on the mature electronic components and equipment on mobile phones to carry out certain transformations, a satellite is manufactured. The manufacturing cost of this satellite itself is very low, and the most expensive part of it is the launch.
If we follow the traditional one-to-one single launch method, such a mobile phone satellite will have to bear the launch cost of the entire rocket, which is very expensive.
Even if one-arrow multi-satellite technology is used to send several such tiny satellites into the sky, the price will be very high evenly.
Therefore, how to reduce costs has become a problem that scientists and technical experts have been thinking about and researching.
Secondly, this kind of micro-satellite is easy to manufacture, transport, launch, and deploy. It is also conducive to launching and deploying a large number of micro-satellites at one time to fight against the enemy's range weapons.
Because of these advantages, the development of small satellites and micro-satellites is very rapid.
In recent years, as the country has increased its opening up in the aerospace field, more and more scientific research institutions and companies have also developed their own small satellites and microsatellites.
Wu Hao and the others saw the broad development prospects of this market, so they launched this project. It is hoped that with the upper stage, many satellites can be launched and transported at one time and transported to different orbits.
In this way, coupled with the retractable launch vehicle, the launch cost spread to each small satellite and microsatellite will be greatly reduced.
This not only allows these R&D teams to take over, but also drives the development of this industry. It is also a good thing for Wu Hao and the others. This move will not only open up the market for these orders, but also greatly promote Wu Hao and the others in the field of aerospace technology, especially spacecraft technology, orbit change technology, and deep space exploration. .
So Wu Hao was very concerned about this project, so he started asking questions.
Hearing Wu Hao's greetings, Yu Chengwu smiled and nodded: "The project is progressing smoothly. We initially plan to divide the entire project into a three-step strategy.
The first step is to develop and manufacture five to ten upper-stage spacecraft, which can meet the current launch needs of the two types of rockets and can send five to ten small satellites to their respective predetermined orbits at one time.
The second step is between ten and thirty, which means we can put up to thirty small satellites or tiny satellites into different orbits.
This has almost reached the maximum transportation load of our Jianmu-2, so this upper stage will also be our main launch force for a long time to come.
In the third step, we plan to increase the scale to about 30 to 100 large upper stages, so as to send about 100 small satellites or microsatellites into different orbits.
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