It is about to enter the proper development stage, and it is expected to be launched in 2022

  ASO-S: The Chinese "Explore the Sun" Sky Eye

  Our ASO-S satellite will carry three instruments, one is called a full-plane vector magnetic imager, which specializes in observing the solar magnetic field; one is called a hard X-ray imager, which specializes in observing solar flares; and the other is called the Lehman Alpha Solar Telescope, which specializes in observing the corona. Mass ejection.

  —— Gan Weiqun, Chief Scientist of ASO-S Satellite Engineering, Researcher of Purple Mountain Observatory, Chinese Academy of Sciences

  ◎Intern Ji Tianyu, reporter Zhang Ye

  In the space 150 million kilometers away from the earth, there is a huge star that glows all the time. Its dazzling light penetrates the atmosphere and brings light and heat to the blue earth. It is the sun.

  The sun is the star most closely related to mankind, and it is also the only star that mankind can study in detail. Through detailed study of the sun, we can have a deeper understanding of the solar magnetic field, solar flares and coronal mass ejection (one magnetism and two Violent).

  "At present, my country's first comprehensive solar exploration satellite, Advanced Space-Based Solar Observatory (ASO-S), is about to enter the stage of proper development." Gan Weiqun, chief scientist of ASO-S satellite engineering and researcher of the Purple Mountain Observatory of the Chinese Academy of Sciences, told Science and Technology Daily reporter.

  This means that the development of the satellite’s engineering prototype is almost complete, and after another year or so, ASO-S is expected to be launched into space in 2022, and the "solar storm" of the 25th solar week will be recorded in detail. "And predict the possible impact of the solar eruption on the earth in time.

  The consequences of the Sun's "powerful" are very serious

  About 4.6 billion years ago, on the spiral arm about 26,000 light-years from the center of the Milky Way, a cluster of molecular clouds began to collapse under its own gravity and gradually formed the sun we are familiar with today.

  Since ancient times, the sun has caused too many human thinking, and we are full of curiosity about this dazzling star.

However, the issue that people are most concerned about is always the impact of the sun on the earth.

  Although the sun and the earth are at an average distance of 150 million kilometers, once the sun "shows its power", it will bring incalculable consequences to the earth.

  On October 31, 2003, a strong magnetic storm erupted from the sun, which caused various degrees of damage to a series of scientific satellites such as GOES, ACE, SOHO, WIND, etc. in Europe and the United States, leading to interference in global satellite communications and affecting the GPS global positioning system. Deviations in positioning accuracy have caused various levels of paralysis in ground and space transportation systems that require instant communication and positioning.

  The reason is that the sun emits a large number of charged high-energy particles, which cause serious damage to the electromagnetic environment of the earth. Among them, sunspots, flares and coronal mass ejections have the most significant impact on the electromagnetic environment of the earth.

  Sunspots exist on the surface of the sun's photosphere, where the magnetic field gathers. With the help of modern technology, scientists have observed that the number and location of sunspots change periodically every 11 years.

  Solar flares are a kind of intense radiation explosion, the most intense local explosion event in the solar system. The wavelength of the light it radiates spans the entire electromagnetic spectrum.

  Coronal mass ejection is another form of energy released by the sun. A huge coronal mass ejection can make billions of tons of matter leave the sun in a short time.

  "From the point of view of natural science, the sun is a very good natural physics laboratory. In addition to the internal physical processes of the sun, the sun's surface, atmosphere, magnetic field, structure, fluctuations, full-band radiation, plasma, fluid laws, etc. We can all conduct observational research." Gan Weiqun said.

  According to calculations, once a coronal mass ejection or other explosive activity occurs, scientists can obtain information at least 40 hours before it affects the earth, so as to make timely protection and avoid possible damage.

  Contribute Chinese power to astronomy research

  Since the 1960s, countries around the world have successively launched more than 70 solar exploration satellites.

  In 2018, the highly anticipated U.S. Parker Solar Probe was launched into space. It observed the sun at an unprecedented close range and has achieved considerable results.

  Why do we need to conduct solar exploration in space?

Gan Weiqun explained that due to the presence of the earth’s atmosphere, only visible solar light and limited radio radiation can be observed on the ground, which only occupy a small part of the broad solar radiation spectrum.

And more waveband radiation, such as most high-energy radiation such as ultraviolet and infrared, X-ray and gamma rays, is absorbed by the earth’s atmosphere before it reaches the ground.

  In July last year, my country’s first Mars exploration mission "Tianwen-1" was successfully launched. After many months, the Chang'e-5 returner carried lunar samples to land safely...In recent years, my country has "lunar exploration". The "fire detection" project is gradually advancing, and major breakthroughs have been continuously made. my country's "Japanese exploration" project is also on the agenda.

  On April 28, 2016, the special background model project "Advanced Space-based Solar Observatory (ASO-S)", a special background model project of the Chinese Academy of Sciences' Space Science Strategic Pilot Science and Technology, passed the project's final review organized by the National Space Science Center of the Chinese Academy of Sciences.

After more than one year of in-depth research and comprehensive demonstration, ASO-S finally obtained the approval of the Chinese Academy of Sciences at the end of 2017.

  As early as 1976, my country tried to propose and implement a solar space exploration satellite plan. In the past few decades, my country has not yet launched a special solar exploration satellite.

Therefore, China's first comprehensive solar exploration satellite, ASO-S, has received close attention.

  "The idea of ​​building this satellite was formed in the 1990s, and it has been continuously revised and improved. It was not until the Chinese Academy of Sciences launched the space science pilot project in 2011 that ASO-S was able to get on track and experienced the first stage of the space science satellite project. Set standard procedures." Gan Weiqun said that ASO-S is expected to complete the launch mission in 2022, and then enter the 720-kilometer-high sun-synchronous orbit as planned and begin to shoulder the heavy task of exploring the sun.

  "In international astronomy, my country's total number of heliophysics research papers has ranked second in the world, but most of the data used in these papers comes from observations from foreign satellites, and we lack original contributions. ASO-S can not only have the first Hand data will also contribute Chinese power to international astronomy research." Gan Weiqun said.

  China's "Explore Japan" satellite carries 3 "magic weapons"

  Compared with the previous more than 70 solar exploration satellites in the world, the biggest feature of the ASO-S satellite is to achieve the scientific goal of "one magnet and two storms", that is, to simultaneously observe the solar magnetic field, solar flares and coronal ejections on a satellite platform. , To study the relationship between the three of them.

  In order to observe "one magnet and two storms", ASO-S will be equipped with three solar exploration telescopes with different functions. Their organic combination is another major feature of ASO-S.

  "Our ASO-S satellite will carry three instruments, one is called a full-plane vector magnetic imager, which specializes in observing the solar magnetic field; one is called a hard X-ray imager, which specializes in observing solar flares; and the other is called the Lehman Alpha Solar Telescope, which specializes in observing solar fields. Coronal mass ejection." Gan Weiqun said that in addition to the combined features of the three instruments, each of the three instruments has its own characteristics.

For example, the full-plane vector magnetic imager has relatively high time resolution; the hard X-ray imager has more probes than similar international instruments, with 99 detectors; the Lehman Alpha Solar Telescope can not only observe the inner corona, but also The Lyman Alpha line itself is a new observation band window.

  Prior to this, my country's "sun-exploring" satellites were blank, and there was not much experience to follow. The key technologies could be described as "harder than climbing to the sky."

Take hard X-ray imagers as an example, three key technologies need to be overcome.

Take the processing of grating as an example. The 99 probes of a hard X-ray imager are equivalent to small eyes. The front of these small eyes are made of hard metal gratings. X-ray photons need to pass through the gaps in the gratings. The narrowest gap is only 18 microns, which is thinner than a human hair.

Gan Weiqun compares the production process to processing a book. First, "paper" with slits is produced, and then the distance between the paper is strictly controlled to form a thick "book" with even gaps.

In addition, factors such as thermal expansion and contraction, harsh space environment, and the launch process must also be considered comprehensively.

  2021-2022 is at the beginning of the twenty-fifth solar cycle. There will be more and more sunspots, the solar magnetic field will become stronger and stronger, and the eruption of the sun will increase. It is expected to reach a peak around 2025. ASO The launch of the -S satellite in 2022 should be a very good time to observe a relatively complete solar cycle.

  After lift-off, the ASO-S satellite will operate in a sun-synchronous orbit 720 kilometers from the surface. The orbit passes through the Earth’s south and north poles at an inclination of 98 degrees. This angle can ensure that the satellite continuously observes the sun for 24 hours.

The expected operating time of the ASO-S satellite will be no less than 4 years.