Xinhua News Agency,At 10:38 on May 5th, my country used the Long March 2D carrier rocket at the Taiyuan Satellite Launch Center, and successfully launched the Jilin-1 Wide 01C satellite and the Jilin-1 Gaofen 03D (27-33) and other 8 satellites. Launch into space.The main star successfully entered the predetermined orbit, and the launch mission was a complete success.
Photo: Xinhua News Agency
Upstream News learned that this is not the first time that China has completed a launch mission of multiple satellites with one arrow.
On the morning of February 27, the Long March 8 Yao-2 carrier rocket successfully launched 22 satellites into the predetermined orbit at the Wenchang Space Launch Site, setting a new record for the launch of multiple satellites with one arrow in my country.
At 14:01 on March 5, the Long March 2C rocket was ignited at the Xichang Satellite Launch Center, successfully sending 7 satellites into the predetermined orbit, and the launch mission was a complete success.
Yang Yuguang, researcher of the Second Academy of Aerospace Science and Industry and vice chairman of the International Astronautical Federation Space Transportation Committee, said that the technology of launching multiple satellites with one arrow has been relatively mature in the world, and the aerospace powers including the United States, Russia, and China have relatively maturely mastered it. this technology. But in fact, the number of satellites launched at a time is not the key, the launch technology is more important.
What is “multiple stars with one arrow”?
The “multiple satellites with one arrow” technology is a launch technology that uses a carrier rocket to send several satellites into the earth’s orbit at the same time or one after the other. This superior launch method can make full use of the carrying capacity of the launch vehicle and reduce the cost of satellite launch.
In 1960, the United States launched two satellites with one rocket for the first time, and achieved three satellites with one rocket a year later. Subsequently, the former Soviet Union and the European Space Agency also mastered this launch technology. In 1981, China used the Storm-1 carrier rocket to put three Shijian-2 satellites into orbit, becoming the fourth country to independently master the technology of launching multiple satellites with one arrow.
With the development of rocket carrying capacity and technologies such as launch and star-rocket separation, the number of satellites launched by “one arrow” has repeatedly hit new highs.
In 2015, my country’s Long March 6 carrier rocket sent 20 satellites into space during its maiden flight mission, setting a record of multiple satellites with one arrow in Asia at that time.
However, in the eyes of aerospace experts, the number of satellites launched is not critical from a technical point of view, and the launch method reflects the technical content.
Multi-orbit is more technical than multi-satellite
Yang Yuguang, a researcher at the Second Academy of Aerospace Science and Industry and vice chairman of the International Astronautical Federation Space Transportation Committee, introduced that gravity loss is the biggest difficulty faced during launch. In theory, launching the launch vehicle at the fastest speed saves the most energy. However, since the earth is a celestial body with a very strong gravitational force, if the rocket speed is not fast enough, gravity will cause huge energy loss and waste a lot of propellant.
According to public information, the take-off thrust of the Long March 2D rocket has reached 300 tons. A 1.2-ton aircraft can be sent into a sun-synchronous circular orbit 700 kilometers away from the earth.
Strong rocket thrust is the key to ensuring the successful launch of multiple satellites with one arrow. If the thrust of the rocket is not enough, even if it is possible to achieve multiple satellites with one arrow, only small satellites can be selected.
In addition, when multiple satellites are launched at the same time, realizing the separation of multiple satellites into different orbits is a top technology for launching multiple satellites with one arrow. Taking the Long March 2D rocket as an example, it not only has a strong carrying capacity, but also has the single-satellite and multi-satellite launch capabilities required by different orbits. That is, after the rocket is launched, it can release different satellites in different orbits according to the design needs. This means that if 8 satellites are launched at a time, these 8 satellites can be distributed at different orbital altitudes in order to meet the needs of different functions.
The world‘s “one arrow with multiple satellites” launch record
On February 15, 2017, India successfully launched 104 satellites into space using the PSLV-C37 carrier rocket at one time, setting a new world record for multiple satellites in one arrow.
The 104 satellites launched this time are dominated by the 730-kilogram Indian “Mapping-2D”, with two 19-kilogram microsatellites and 101 nanosatellites less than 10 kilograms. The Indian rocket’s sun-synchronous orbit carrying capacity is only 1.5 tons, and no breakthrough has been made in carrying capacity. This is still a big gap from China’s launch of multiple satellites with an average weight of nearly 120 kilograms per satellite. In addition, India uses one arrow and one orbit technology, which means that after all satellites are sent to the same height, they are released in sequence like a goddess scattered flowers, and it is impossible to release satellites in multiple orbits.
On January 24, 2021, SpaceX completed the “Transporter 1” launch mission. The Falcon 9 rocket carried 143 satellites into space, setting a new record for the number of satellites launched in a single global launch.