Fast production and fast launch, new "star" and new concept

As the aerospace industry develops rapidly, satellite services are becoming more and more extensive and deeply integrated into our lives, so that the efficiency of traditional satellite launches is increasingly unable to meet the needs of aerospace planners and customers. What are some ways to manufacture and deploy satellites faster? Will there be some disruptive future solutions that are mind-blowing? Let's take a look.

"Basketball" and "Tablet" have many varieties

We enjoy radio communication and Internet services every day, but as people's activities expand and exchanges between regions strengthen, traditional service means are gradually showing their shortcomings. Cost and technical limitations force towering base station signal towers to be unable to cover all target areas, and high-speed optical fibers cannot connect every household. What if "hikers" lose their mobile phone signals in the mountains and forests? If Antarctic scientific expedition personnel cannot video chat with their families for a long time, will it affect their physical and mental health and work efficiency?

To solve these problems, the aerospace industry has planned a grand Skynet plan, hoping to build a satellite network system that covers 100% of the Earth's surface and provides various services in real time by relying on a large number of high-performance satellites. For example, SpaceX's "Starlink" plans to deploy 42,000 satellites. Perhaps by then, a suitcase-sized client server can provide stable communications for tens of thousands of square kilometers, and even a celebrity can broadcast a smooth live video broadcast to his fans on Mount Everest.

Schematic diagram of Starlink satellite deployment

Behind the beautiful vision, there is a need for real material support, that is, a huge number of satellites in orbit, and the first step to overcome is the difficulty of rapid satellite manufacturing.

The traditional satellite manufacturing process has been described as an "isolated island". Enjoying the luxury of "private customization" requires a lot of time and cost from program demonstration to detailed design, production, delivery, integrated assembly and testing.

In the future, miniaturization and integration will be the key to satellite manufacturing technology, while ensuring that satellite performance is "sufficient" and easy to mass produce. In this regard, SpaceX's technology is temporarily in the leading position, and the "Starlink" special launch has stabilized at around "60 satellites per rocket". Musk even revealed that the new generation of satellites is only the size of a standard basketball. The promotional video shows the spectacular scene of the future "Starship" launching the "Starlink" second-generation satellites on a large scale. The satellites are densely arranged in disks, and the disks are "spitted out" by the rocket, which shows how small the satellites are compressed.

China's aerospace units are also working hard on satellite miniaturization and integration, as this not only contains huge commercial interests, but also involves national security competition. Recently, my country's new generation of stackable flat-panel satellites has entered the pre-prototype research stage.

According to public information, relevant companies have gradually reduced manufacturing costs and improved production efficiency in the process of satellite design optimization, new material substitution, component process simplification, and continuous iteration. They have reached an annual output of about 100 satellites and are expected to produce hundreds of satellites in the future.

Specifically, due to the successful use of 3D printing technology, researchers have improved the processing technology of payloads such as high-frequency micro-waveguides and high-performance antennas, compressed the payload space to 1/3 of the traditional occupied space, and also improved comprehensive indicators, such as the performance of some single machines and systems.

The appearance of China's new generation of satellites is also beyond many people's expectations. Unlike the square boxes or large spheres we often see, it is flat, with small devices and wiring harnesses densely arranged on its surface. The ultra-thin solar wing that matches it is a 12-fold "sliding door" structure, composed of multiple solar panels connected together. After folding and compacting, the thickness is said to be only a few centimeters.

It is conceivable that in the near future, dozens or even hundreds of new-generation satellites resembling tablet computers will be stacked in the payload cabin of the Long March rocket. They will form China's satellite rapid response force, rushing into space in groups to take up their posts and "dedicate" themselves to the great cause of all-round real-time communications on Earth and space Internet.

"Giant Whale" and "Cannon" come to help

After satellites have been miniaturized and integrated, it is necessary to try to innovate the launch and deployment methods. Some aerospace researchers and enthusiasts have come up with many unique new ideas. Their goals are the same: to reduce launch costs and quickly deploy satellites in large numbers.

First, there is the super airship launch plan. Similar to the principle of hot air balloons, airships do not need to consume their own energy to rise, but use the buoyancy of air everywhere in the atmosphere. As long as the airship is large enough, its load capacity will be amazing, enough to place thousands of micro satellites, and it is also possible to fly to the stratosphere tens of thousands of meters high.

The biggest appeal of this plan is that it uses the lift of the air. The airship will lift a large number of satellites into near-space, which is expected to significantly save launch costs. It can also move freely on the horizontal plane, flexibly grasp the launch time, and provide sightseeing services.

Imagine a deep blue "giant whale" cruising at an altitude of tens of thousands of meters. Its spindle-shaped surface is actually a huge solar panel that can provide power for the airship and store energy for launching satellites. Until a certain moment, colorful fireworks flashed around the "giant whale". In the magical halo, satellites flew to their coordinates in space.

Secondly, there is the electromagnetic gun launch plan. The electromagnetic gun is a "cannon" that uses the Ampere force of the electromagnetic field to accelerate the projectile. In the 1970s, Western countries conducted initial experiments on electromagnetic guns and successfully accelerated a 2-gram object to 11,000 meters per second. This has exceeded the first cosmic speed. In other words, if air resistance is not taken into account, this 2-gram little guy has the potential to become a mini satellite of the earth. As satellites become smaller and lighter, some countries have tested super electromagnetic guns with greater power and energy. The idea of ​​using electromagnetic guns to launch satellites naturally appeared in the minds of aerospace researchers.

Electromagnetic gun developed by the United States

Countries have been researching electromagnetic guns for many years, but have yet to put them into practical use. There are two main reasons: first, electromagnetic guns and their supporting equipment are huge in size, making them difficult to install on aircraft, ships, and vehicles; second, electromagnetic guns are too expensive to fire shells, with the operating cost of a single shell being tens of thousands of dollars.

However, if electromagnetic guns are used to launch satellites, these disadvantages seem to be negligible, or even become advantages: on the one hand, no matter how many electromagnetic gun-related equipment there are, the base is large enough to accommodate them, and the area occupied is much smaller than that of traditional rocket launch bases; on the other hand, the launch cost of tens of thousands of dollars is a drop in the bucket compared to the manufacturing cost and fuel cost of traditional rockets.

Of course, electromagnetic guns still face many technical challenges in launching satellites. For example, to what extent can satellites be miniaturized in the future? If satellites can be compressed to the size of an apple, the energy consumption pressure of electromagnetic guns will definitely be reduced a lot. In addition, can satellites remain safe under huge acceleration loads and strong electromagnetic fields? I believe that aerospace technology will give a gratifying answer in the future. But there is one thing that makes people curious: will the satellite "cannon" fire single shots or continuously? The mission of launching tens of thousands of satellites may be completed in a week. (Author: Sun Fei)