Source: People's Daily client
Just now, China's first solar exploration science and technology test satellite "Xihe" was successfully launched at the Taiyuan Satellite Launch Center! This satellite is not good, achieving a breakthrough in China's solar exploration zero, marking China's space exploration officially entered the era of "sun exploration"! Moreover, the "Xihe" satellite is extraordinary as soon as it is shot, and the space exploration of the solar Hα band spectral imaging is realized for the first time in the world, filling the gap of high-quality observation data in the source area of the solar explosion, which is of great significance to China's space science exploration and satellite technology development.
From Chang'e's "lunar exploration" to Tianwen's "fire exploration" to Xihe's "sun exploration", China's aerospace power construction has taken solid steps. What is the use of detecting the sun? What are China's solar exploration plans? What are the unique features of the Xihe satellite? The reporter interviewed the relevant experts of the China National Space Administration for the first time.
High-definition simulation of the Solar Exploration Science and Technology Experiment Satellite
Why probe the sun?
In the middle of the solar system, human beings cannot help but be curious and inquired about the center of the solar system, the sun that brings light and energy to the earth. Scientists say that about 4.6 billion years ago, the sun was about 26,000 light-years away from the center of the Milky Way, formed by the collapse and condensation of nebulae under its own gravitational force, and the sun has a lifespan of about 10 billion years and is currently in its prime. The diameter of the Sun is 1.39 million kilometers, which is 107 times that of the Earth, and the mass is 330,000 times that of the Earth, accounting for 99.87% of the total mass of the entire solar system, which can be said to be the absolute master of the solar system. It is a huge star that undergoes hydrogen, helium fusion, and emits light and heat all the time.
"The role of the sun on the evolution of the earth and the development of human civilization is indispensable, and at the same time, the influence of the sun on the earth is also omnipresent, mainly reflected in the fact that the solar eruption produces a large number of charged high-energy particles, causing serious damage to the earth's electromagnetic environment, especially sunspots, flares and coronal material ejections on the earth's electromagnetic environment is the most significant." Zhao Jian, director of the Earth Observation and Data Center of the China National Space Administration and chief designer of the high-resolution Earth observation major special project, told reporters that the solar activity cycle is about 11 years, and 2021 to 2022 is the beginning of the 25th solar activity cycle since human records have been recorded, and the world has entered a new peak period of solar research.
From a worldwide perspective, since the 1960s, with the rapid development of space technology, more than 70 solar observation satellites have been launched around the world, mainly concentrated in developed countries such as the United States, Russia, and Japan, focusing on the observation and research of sunspots, flares and coronal mass ejection.
What are some of the representative solar probes? Experts cite a few examples, such as the United States launched the world's first twin solar observation satellite - the Sun-Earth Relationship Observation Platform in October 2006, which performed three-dimensional imaging of sunspot outbreaks to help scientists study the impact of the sun's surrounding environment and solar activity on the entire solar system; in January 2009, Russia launched the "Coronas" solar exploration satellite to explore the impact of the sun's internal structure and solar activity on the Earth's climate, atmosphere and biosphere; in 2018, the United States "Parker" The solar probe was launched to explore the structure of the sun at close range, and considerable results were obtained.
What are China's solar exploration plans?
International solar exploration is in full swing, and China's solar exploration program certainly cannot be left behind. During the "13th Five-Year Plan" period, the China National Space Administration organized the research of China Aerospace Science and Technology Corporation, Nanjing University, Chinese Academy of Sciences and other units to formulate a roadmap for the development of space science research, and began to implement it in an intensive manner.
"Detecting and studying solar activity and proposing countermeasures can reduce or circumvent adverse effects on Earth. As a space power, it is very necessary for China to carry out solar exploration activities in a timely manner. Zhao Jian revealed that China has formulated two solar exploration plans, namely the "Xihe" and "Kwa father" exploration plans, which are China's program and China's contribution to solar exploration. Xihe is the sun goddess in ancient Chinese mythology, the sun god who rules time and calendar, and is known as the mother of the sun. The "Xihe" has realized the ice-breaking journey of China's solar exploration, and the "Kwafu" plan is to develop and launch an advanced space-based solar observatory satellite to conduct scientific observations of the sun, which has been included in the pilot plan of the Chinese Academy of Sciences and is scheduled to be launched next year.
In addition, China is demonstrating the follow-up solar exploration development plan, scientists hope to implement in accordance with the multi-perspective detection in the ecliptic plane, the detection of the large inclination of the solar polar region and the observation of the sun's approach, to further understand the structure of the sun, determine the three-dimensional structure of solar activity, master its mechanism and activity law, so as to benefit mankind, and seek benefits and avoid harms.
Where is the innovation of xihe?
According to experts, the full name of the "Xihe" satellite launched this time is the solar Hα spectrum detection and double super platform science and technology test satellite, and the main scientific payload is the solar space telescope. Xihe star weighs 508 kilograms, has a design life of 3 years, and operates in a sun-synchronous orbit with an altitude of 517 kilometers and an inclination of 98 degrees, which will pass through the north and south poles of the earth and be able to observe the sun continuously for 24 hours.
Zhao Jian said that the "Xihe" solar exploration plan closely focuses on the hot issues of solar exploration and proposes a solar exploration model with Chinese characteristics, such as the first spectral imaging detection of the Hα band of the space sun in the world; and the first proposed new methods and new technologies for astronomical spectral speed measurement and navigation, which are of great significance.
What are solar Hα spectral lines?
Experts explain that the solar Hα line is one of the best spectral lines to study the response of the solar activity in the photosphere and the chromosphere, through the data analysis of the spectral line, you can obtain the changes in the atmospheric temperature, speed and other physical quantities of the solar burst, and study the dynamic process and physical mechanism of the solar burst.
"Previously, Hα spectral lines could only be detected on Earth, which was disturbed by the atmosphere and the detection data was not continuous and unstable. Now through the detection of 'Xihe' and high-resolution imaging, the spectrum on the 16 million points of the full day surface can be obtained within 46 seconds, and the two-dimensional image of the color ball and the photosphere can be obtained at more than 300 wavelength points at the same time, which can more accurately obtain the changes in the temperature and speed of the atmosphere when the sun bursts, and then establish a complete physical model of the solar burst from the photosphere to the corona. This has important implications for observations of the sun's underlying atmosphere and solar eruptions. Zhao Jian introduced that the relevant experiments carried out by the "Xihe" satellite in orbit are the first time in the world to conduct Hα spectral line research in space, which is expected to obtain scientific output with international influence and will significantly improve China's international influence in the field of heliophysics.
It is understood that the current international solar exploration has become a hot spot, and the number of papers published in the field of solar observation in China has ranked second in the world, but the data used are from foreign satellite data. "After the successful launch of xihe, this passive situation will be broken, and China will set up a satellite data science committee to formulate data policies for domestic and foreign scientists to study, use, and share satellite exploration data, strive to produce original scientific achievements, and make Chinese contributions to the cause of human science." Zhao Jian said.
What does the internationally pioneered "double super" platform look like?
The innovative significance of the "Xihe" satellite is not only reflected in the solar exploration, it adopts the internationally pioneered double ultra-new technology satellite platform, which realizes the ultra-high precision and ultra-high stability control of the payload in orbit, which is two orders of magnitude higher than the current satellite platform of the same inertia, which is called the "double super" platform in the industry, which will promote the revolutionary and leapfrog development of China's high-precision satellite platform technology.
It is understood that with the continuous development of China's aerospace industry, the demand for high-performance satellite platforms for various space missions such as Earth observation and space science is becoming more and more urgent, especially satellite platforms with ultra-high pointing accuracy and ultra-high stability indicators, which is one of the key "card neck" technologies that restrict the subsequent development of the aerospace industry.
"Traditional satellites use a design method of solid connection between the platform bay and the payload bay, so vibrations from the moving parts of the platform capsule will inevitably be transmitted to the payload, resulting in a decrease in the quality of the observation." Cheng Weiqiang introduced that with the strong support of the China National Space Administration, the satellite development team adopted the new overall design method of "dynamic and static isolation non-contact" for the first time in the world, physically isolated the platform module from the load bay, and concentrated micro-vibration sources such as flywheels and solar sails in the platform cabin, and the solar Hα spectrometer was placed in the load bay, and the magnetic levitation control technology and actuator were used to achieve physical non-contact isolation of the two, which not only blocked the transmission path of the micro-vibration of the platform cabin, but also solved the impact of the thermal deformation of the platform cabin on the load bay. Improve the accuracy and stability of load control by more than two orders of magnitude. The successful launch of "Xihe" marks the smooth entry into the application stage of the "ultra-high pointing accuracy" and "ultra-high stability" dual-super satellite structure platform independently developed by China.
At the same time, the "Xihe" satellite will also verify in orbit wireless energy transmission, inter-cabin wireless communication, inter-cabin laser communication, repeated connection release, inter-cabin cable shedding and storage, atomic frequency detector solar navigator and many other new technologies and new products.
Zhao Jian said that after the successful on-orbit test of the "Xihe" high-performance technology satellite platform, it is the first time in the world that the magnetic levitation technology will be applied to the spacecraft for engineering application, which will greatly improve the level of China's space observation technology. In the future, the "double super" platform technology will also be promoted and applied in a new generation of space missions such as high-resolution detailed earth survey, large-scale stereo mapping, solar stereoscopic detection, and exoplanet discovery, so as to promote the leapfrog development of China's space science field and aerospace technology field.