China to launch solar probe to unexplored L5 point in 2026

SHANGHAI - China is planning to launch a solar exploration satellite to a previously unexplored orbit between the Earth and the sun in order to carry out solar probe and space weather monitoring.

The appraisal work of Xihe 2 solar exploration mission to the Sun-Earth L5 Lagrangian Point are in the pipeline, said Fang Cheng, one of the satellite's designers, at the ongoing 10th Conference on Advanced Space Technology in Shanghai.

The Chinese team is working hard to launch the solar probe into planned orbit around 2026, according to the appraisal plan.

The Sun-Earth Lagrangian L5 point, approximately 150 million kilometers away from Earth, is a uniquely advantageous location for space weather research and monitoring, as it enables imaging of solar activity at least three days prior to a terrestrial viewpoint and measures the solar wind conditions four to five days ahead of Earth impact.

"The Sun-Earth L5 point is still a virgin place for exploration," said Fang, a professor from Nanjing University. "It is scientifically meaningful and feasible in engineering."

Xihe 2, a mission launched by Nanjing University, China Meteorological Administration and Shanghai Academy of Spaceflight Technology, is expected to investigate the origin and evolution of the magnetic field in the solar active region, and reveal the three-dimensional structure and physical mechanism of solar bursts.

It can also provide data for timely early warning and accurate forecasting of space weather, according to Fang.

On Oct 14, 2021, China sent its first solar exploration satellite Xihe into a sun-synchronous orbit to conduct solar H-alpha spectral imaging.