China Opens Xihe-2 Solar Observatory to International Cooperation
Summary: On April 24, 2026, CNSA officially released the Xihe-2 International Cooperation Opportunity Announcement at the 11th China Space Day ceremony, offering approximately 15kg of payload resources and inviting international partners to jointly explore solar science.
Credit: CNSA
On April 24, 2026, at the main venue ceremony for the 11th China Space Day in Chengdu, Sichuan Province, the China National Space Administration (CNSA) officially released the Xihe-2 International Cooperation Opportunity Announcement, welcoming international partners to participate in the Xihe-2 mission, jointly explore solar science, and expand human understanding of the Sun.
Xihe-2 Mission Overview
Xihe-2 is China's next-generation solar observation satellite, with its target orbit at the Sun-Earth Lagrange Point L5. This marks China's first solar observation probe launched to the Sun-Earth L5 point, carrying significant scientific importance.
Primary Scientific Objectives
The Xihe-2 mission aims to achieve the following scientific objectives:
- Three-Dimensional Solar Observation: Unprecedented stereoscopic observation of the Sun from L5 point, compensating for limitations of single-point observation
- Solar Active Region Magnetic Field Studies: In-depth research on the three-dimensional structure and dynamic evolution of solar active region magnetic fields
- Three-Dimensional Structure and Physical Mechanisms of Solar Eruptions: Revealing the formation mechanisms of solar flares and coronal mass ejections (CMEs)
- Solar Eruption Propagation Research: Clarifying the propagation patterns of solar eruption events through interplanetary space
- Space Weather Forecasting Improvement: Providing support for timely early warning and accurate prediction of space weather
International Cooperation Opportunity
According to CNSA's announcement, the international cooperation payload resources for the Xihe-2 mission are approximately 15 kg. Specific cooperation modalities include:
- International scientific payloads will be installed on the Xihe-2 spacecraft platform through co-manifested missions
- Joint space science exploration and research activities
CNSA welcomes active participation from research institutions and international organizations worldwide. Detailed technical specifications are available through the CNSA official website.
Scientific Significance
The Sun-Earth Lagrange Point L5 is located along the Sun-Earth line, approximately 150 million kilometers from Earth. From this unique observation position, Xihe-2 will enable:
- Advance Early Warning: Several days of advance warning for solar eruption events compared to Earth-based observations
- Stereoscopic Observation: Complementary to Earth-orbit observation stations for three-dimensional solar observation
- Continuous Monitoring: Long-term continuous monitoring of solar activity
This mission will provide critical data support for better understanding solar activity and preventing space weather disasters.
China's Solar Exploration History
Xihe-2 is China's next-generation solar observation satellite following Xihe-1:
| Satellite | Launch Date | Orbit | Primary Mission |
|---|---|---|---|
| Xihe-1 | October 2021 | Sun-synchronous orbit | Solar Hα spectral imaging |
| Xihe-2 | Planned | Sun-Earth L5 | Stereoscopic observation, international cooperation |
Background: 2026 marks the 70th anniversary of China's space industry and the 11th China Space Day. This year's theme is "70 Years of Journey to Space, Exploring the Heavens Together." The Xihe-2 international cooperation announcement reflects China's philosophy of open collaboration and shared achievements in space exploration.