From hand-ground lenses to Xihe solar space missions: an interview of Professor Cheng Fang

The Sun is an ordinary star among the hundreds of billions of stars in the Milky Way, yet it is the only star that humanity can currently observe with high temporal and spatial resolution. Solar observation and research carry great scientific significance and practical value. These enable us to understand fundamental astrophysical processes regarding elementary particles, magnetic fields and celestial eruptions. Moreover, eruptions of the Sun bring hazardous space weather and affect the safety of the Earth. Professor Cheng Fang (), an academician of the Chinese Academy of Sciences (CAS), is a pioneer of China's research on solar active-region physics and development of solar observation instruments. He led the construction of China's first solar tower telescope and the Optical and Near-infrared Solar Eruption Tracer, and served as the chief scientific advisor for China's first solar space mission, the Chinese Hα Solar Explorer (CHASE), also known as Xihe (). Currently, he is spearheading the construction of the 2.5-meter Wide-field High-resolution Solar Telescope (WeHoST) and the LAgrange-V Solar Observatory (LAVSO, also known as Xihe-2). In this interview, we traced Prof. Fang's academic journey and the development of China's solar instruments: from virtually zero and hard beginnings, to the deployment of large ground-based facilities and space missions, and further progress toward a three-dimensional solar observation system. He also shared his scientific spirit as a senior scientist who has devoted decades to uncovering the mystery of the Sun.