China succeeds in two-way high-speed laser communication over 400,000 km between Earth and the Moon

[Financial News] China has succeeded in two-way high-speed laser communication between the Earth and the Moon, China Central Television (CCTV) reported.
CCTV said on the 31st, citing the Space Application Engineering and Technology Center of the Chinese Academy of Sciences, that China recently succeeded in establishing a two-way laser communication link over a distance of more than 400,000 kilometers in an Earth-Moon laser communication experiment, achieving high-speed laser communication.
It added, "This means that space laser communication has formally moved from low-Earth orbit into the Earth-Moon space," and emphasized that it "will provide an important technological pillar for crewed lunar landings, the construction of a lunar scientific research base, and deep-space exploration."
Space laser communication is a method of transmitting information using lasers. It offers a wide bandwidth, fast transmission speeds, and strong precision and security. However, it is inevitably affected by atmospheric conditions, and technical challenges grow as the distance increases.
According to CCTV, Chinese researchers also succeeded in improving the transmission efficiency of lunar-Earth laser communication and achieved communication speeds of 1.25 Mbps for uploads and 100 Mbps for downloads.
The outlet added that under the previous microwave-based communication method, transmitting a high-resolution 8K image file of the lunar surface would take four to five minutes, whereas at the 100 Mbps speed achieved by the Chinese researchers, the file could be downloaded in just 12 seconds.
CCTV explained that Chinese researchers comprehensively considered various factors, including satellite orbit, telescope installation errors, atmospheric refraction, and laser flight time, and devised a method that allows a satellite in space and a telescope on the ground to keep aiming at each other even while both are moving. This solved one of the main problems in laser communication: poor alignment.
It also reported that the researchers developed an "ultra-sensitive detector" capable of detecting single photons and an algorithm that can identify complex signals, helping address the problem of signal weakening over long distances.
[email protected] Lee Seok-woo, international affairs Reporter