China achieves hours-long two-way laser communication with high-orbit satellite

(ECNS) - Chinese researchers have established a stable two-way laser communication link with a geostationary satellite nearly 40,741 kilometers (25,300 miles) from Earth. The system achieved data transmission speeds of 1 gigabit per second in both directions and maintained the connection for more than three hours, the Chinese Academy of Sciences said on Monday.

Globally, satellite-to-ground laser communication research has focused either on maximizing one-way downlink speeds or enabling sustained two-way communication in high orbit. The latter is seen as critical for operational space systems requiring continuous interaction.

The latest experiment extended stable two-way communication in high orbit from minutes to hours, the institute said, allowing satellites to not only transmit data at high speed but also receive instructions in real time.

The system used a domestically developed 1.8-meter ground-based laser communication station designed to capture weak signals from roughly 40,000 kilometers away. It incorporated precision pointing control and adaptive optics technologies to correct atmospheric interference and maintain stable, high-speed transmission.

The Academy said the technologies tested could support future integrated space-ground communication networks, including high-orbit satellites relaying data from low-Earth-orbit satellites. It added that the signal acquisition capabilities could provide technical groundwork for future laser communication links with deep-space probes.

(By Zhang Jiahao)