China has begun work on a follow‑on solar observatory, planning to launch “Xihe‑2” to the Sun‑Earth L5 Lagrange point in 2028–2029. The project was unveiled at a kickoff meeting and scientific symposium, and state media reported that the mission will observe the Sun from new spectral bands and geometries to create three‑dimensional views of solar activity.
The name Xihe draws on ancient Chinese astronomy and mythology: the first satellite in the series, launched in October 2021 as a technology and science demonstrator, marked China’s formal entry into dedicated space‑based solar observation. Nanjing University academician Fang Cheng told reporters that the original Xihe has already outlived its designed service life but continues to operate satisfactorily, and that Xihe‑2 will expand the program’s scientific reach.
Positioned roughly 60 degrees ahead of or behind Earth in its orbit, the Sun‑Earth L5 point offers a side‑on vantage that reveals active regions and magnetic structures days before they rotate into Earth view. That advance perspective is valuable for forecasting coronal mass ejections and other disturbances that can impact satellites, power grids, aviation and crewed missions, because it complements near‑Sun monitors at L1 and close‑in probes by providing lead time and stereoscopic geometry.
China’s decision to target L5 is also a technical and strategic choice. Western missions such as NASA’s STEREO pair and a host of L1 platforms have demonstrated the science value of multiple vantage points; a dedicated L5 observatory would strengthen China’s independent capability in heliophysics and space‑weather warning, and could supply data that national operators rely on to harden critical infrastructure.
The timetable—launch in the second half of the decade—comes as governments and industries worldwide push to improve space‑weather resilience. Solar activity has been variable but remains a prominent risk for an economy ever more dependent on satellite navigation, communications and high‑voltage transmission; a reliable L5 node could translate into measurable reductions in forecasting uncertainty and earlier operational responses.
Beyond practical applications, Xihe‑2 signals the maturing of China’s space science program. The mission will test instruments and observation strategies that deepen understanding of solar magnetic topology and heliospheric dynamics, while raising questions about data sharing, international collaboration and the degree to which China will integrate its observations with global forecasting systems.