As part of the experiment announced on February 26 by the European Space Agency, a ground-based laser terminal developed by Airbus established a reliable connection with the Alphasat satellite, located at an altitude of approximately 36,000 kilometers. For several minutes, a continuous data transmission channel was maintained at a speed of 2.6 Gbit/s.
Representatives of Airbus noted that one of the main challenges of such experiments is the need for precise targeting of the laser beam. At a distance of 40,000 kilometers, even the slightest vibrations of the platform, movements of objects, and atmospheric distortions require constant correction and high precision in control.
At the same time, the Institute of Optoelectronics of the Chinese Academy of Sciences also reported its successes. Scientists established a bidirectional laser communication channel with a satellite located about 40,000 kilometers away. For the experiment, a ground-based laser station with an aperture diameter of 1.8 meters was used, which required about four seconds to lock onto the target. The connection was maintained for three hours.
Data transmission was symmetrical — at a speed of 1 Gbit/s both towards the satellite and back. The Chinese project paid special attention to the closed-loop control guidance system, which provided microscopic correction of the beam's position in real time. A combination of adaptive optics, which compensated for atmospheric turbulence, and coherent reception with mode diversity was used to receive the signal, allowing for a reduction in signal fading.
The Institute emphasizes that such technologies not only enable the transmission of large volumes of data but also allow for the uploading of complex control algorithms to satellites. In their opinion, this could transform satellites from simple relays into nodes with elements of autonomous information processing.
Against the backdrop of these achievements, the contrast with low-orbit systems becomes evident. Satellites at altitudes of less than a thousand kilometers are already demonstrating speeds in the hundreds of gigabits per second; however, geostationary orbit remains a more challenging environment due to signal delays and strict requirements for communication stability. Therefore, successes in the field of laser channels at such distances are seen as a significant step towards the creation of high-speed space networks of the future.
The article was published: Laser internet reaches geostationary orbit: Europe and China transmitted data at speeds of up to 2.6 Gbit/s on the K-News platform.
