https://www.cas.cn/cm/202608/t20260827_5119121.shtml
After more than a year of in-orbit testing, a Chinese research team has successfully established a two-way laser link spanning over 400,000 kilometers between Earth and the Moon and verified high-speed Earth-Moon laser communication capabilities in orbit for the first time. This marks the official expansion of China’s space laser communication from low-Earth orbit into Earth-Moon space.
Led by the Space Utilization Center, the project involved collaboration with Zhijiang Laboratory to develop the laser communication test payload for the DRO-A satellite, and with the Yunnan Observatories and the Shanghai Institute of Microsystem and Information Technology (both under the Chinese Academy of Sciences) to develop and construct the ground-based laser communication system.
The space laser communication is a method of transmitting information using lasers. Compared to traditional microwave communication, it offers advantages such as high bandwidth, high speed, precise directionality, strong security, compact and lightweight equipment, and the ability to perform high-speed, flexible two-way transmission and reception.
The vast distances of deep space—hundreds of thousands of kilometers—present three major challenges that have long plagued the field of deep-space laser communication:
- stringent pointing accuracy requirements,
- extreme signal attenuation, and
- difficulties in increasing transmission rates.
For this test mission, the research team has proposed a two-way acquisition and tracking scheme suitable for ultra-long distances and extremely weak signal conditions. The tests have achieved initial communication rates of 1.25 Mbps for the uplink and 100 Mbps for the downlink, laying a solid foundation for further increasing communication speeds.
The research team believes that with the accelerating pace of global lunar exploration, crewed moon landings, and the construction of lunar research stations, Earth-Moon space is poised to experience a “data explosion.” The “information superhighway” between Earth and the Moon has now been established, paving the way for high-speed data transfer for China’s crewed lunar landing missions, the construction of lunar research stations, and deep-space exploration.
Image: Schematic diagram of Earth-Moon scale two-way laser communication. (Image courtesy of the Technology and Engineering Center for Space Utilization, Chinese Academy of Sciences)
