An illustration of a solar eruption. Depositphotos.

China Launches 859-Kg Satellite to Study the Sun

China launched its Advanced Space-based Solar Observatory (ASO-S), known in Chinese as Kuafu-1, an 859-kg satellite that will study the Sun with unprecedented detail.


In furtherance of the country’s quest to unravel the mysteries of the Sun, China launched a solar exploration satellite into space on Sunday. As reported by Xinhua, the Advanced Space-based Solar Observatory (ASO-S), known in Chinese as Kuafu-1, was successfully launched on the Long March-2D rocket at 07:43 am (Beijing Time). This 859-kg satellite will begin normal operations 720 kilometers away from the Earth after four to six months of testing. As a result, space weather forecasting data will be supported by the study of the causal relationship between solar magnetic fields and solar flares, and coronal mass ejections.

Dedicated to Kuafu, the mythical Chinese giant who indefatigably chased the sun, the observatory will extend its working hours to 96 percent of the year. Observations from space are not impacted by the rotation of the Earth, whereas those from Earth can only view the Sun during daylight hours. According to Gan Weiqun, principal scientist of CAS’ Purple Mountain Observatory (PMO), Kuafu-1 is capable of probing the Sun 24 hours a day most of the year. The longest time-out it experiences each day is 18 minutes when briefly running through Earth’s shadow between May and August.

Extraordinary data

During its 4-year lifespan, the solar probe is expected to accumulate and transmit some 500 gigabytes of data a day. This is equivalent to tens of thousands of high-resolution images. According to Huang Yu, associate chief designer of ASO-S science application system, the onboard detectors can take pictures every few seconds or minutes and quickly increase the shutter speed to only one second during solar eruptions in order to capture solar activities in greater detail.

A 2,048-core powerful computer mounted at the PMO will decode data from space delivered by three ground stations in Sanya, Kashgar, and Beijing over the next four years. This all-rounder satellite designed specifically for solar detection has three payloads on board: the Lyman-Alpha Solar Telescope (LST), the Hard X-ray Imager (HXI), and the Full-disk Vector MagnetoGraph (FMG).


Xihe, a pathfinder in China’s solar exploration, was launched into space in October 2021 as the first milestone in the country’s solar exploration initiative. The Xihe satellite is operated in a sun-synchronous orbit at an average altitude of 517 km, with its main scientific payload a solar H-alpha imaging spectrometer. This instrument determined for the first time a fine structure of spectral lines of solar H-alpha, SiI, and FeI in orbit.

Solving the Solar puzzle

Kuafu-1 will add yet another piece to our host star’s spectral puzzle. Lyman-alpha light emitted from the full disk of the sun can be seamlessly collected by the LST installed on it. Approximately 70 percent of the solar mass releases neutral hydrogen spectra through Lyman-alpha, which is the strongest ultraviolet emission line affecting Earth’s ionosphere.

Feng Li, the LST data scientist from PMO, said the full-disk Lyman-alpha observations might reveal new solar physics. “They’re the first of its kind in the world that images from the disc center to a 2.5 solar radius,” he explained. On Kuafu-1, HXI will capture electrons accelerated between 30 and 200 keV in non-thermal high-energy solar flares and investigate them with more than 90 tungsten optical gratings.

Su Yang, HXI’s data scientist from the PMO, explained that a single centimeter-sized grating has thousands of slits, the smallest of which is 18 microns wide. Arrays of this kind are like compound eyes for X-rays because they take in the big picture while seeing the details simultaneously. The farthest reaches of the universe are now within reach of human observation, but the sun remains “the only star that we can study closely, Gan says.


Our knowledge of the sun is far from comprehensive, and it remains unclear how solar flares and CMEs could affect our planet, said Gan. As far as humankind is concerned, the sun is the most familiar and strangest star. Kuafu-1 is here to help.

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Written by Ivan Petricevic

I've been writing passionately about ancient civilizations, history, alien life, and various other subjects for more than eight years. You may have seen me appear on Discovery Channel's What On Earth series, History Channel's Ancient Aliens, and Gaia's Ancient Civilizations among others.

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