Chinese scientists have successfully transmitted data from a satellite in geostationary orbit at a rate of 1 gigabit per second (Gbps), a speed five times faster than SpaceX’s Starlink network. The feat was accomplished using a remarkably low-power 2-watt laser from an unnamed satellite positioned more than 36,000 kilometers above Earth, an altitude over 60 times higher than Starlink’s low-Earth orbit satellites.
This breakthrough redefines the possibilities of high-altitude data transmission, demonstrating that immense speeds can be achieved with minimal power, equivalent to that of a night light. Starlink, which operates just a few hundred kilometers from the planet’s surface, currently offers maximum speeds of a few hundred megabits per second.
Overcoming a Key Atmospheric Challenge
A primary obstacle for satellite laser communications has long been Earth’s atmospheric turbulence. This phenomenon scatters laser light, causing signals to become weak and distorted by the time they reach ground receivers.
Previous methods to combat this issue, such as Adaptive Optics (AO) to correct distorted light and Mode Diversity Reception (MDR) to capture scattered signals, were insufficient on their own, especially under strong turbulence.
The Chinese research team, led by Professor Wu Jian of Peking University of Posts and Telecommunications and Liu Chao of the Chinese Academy of Sciences, developed a groundbreaking solution they call “AO-MDR synergy.”
This innovative technique combines both methods to effectively stabilize the laser’s path and preserve communication quality, even when dealing with extremely low signal power.
The Experimental Setup
The successful test was conducted at the Lijiang Observatory in southwest China. A ground-based 1.8-meter telescope received and decoded the laser signal from the satellite. This receiving system was equipped with 357 precision micro-mirrors capable of reshaping the warped laser light to reduce distortion in real-time.
Furthermore, a specialized multi-plane converter guided by a custom chip-based algorithm split the incoming light into multiple channels. The system then selected the strongest signals and merged them, dramatically improving signal reliability.
This method increased the chance of receiving a usable signal from 72% to over 91%, a crucial improvement for transmitting high-value data. The findings were published in the peer-reviewed journal Acta Optica Sinica.
This achievement is another milestone for China’s space laser communication program, following a 2020 record set by its Shijian-20 satellite which achieved a 10Gbps downlink. As the global competition for satellite-based internet intensifies, this advancement highlights China’s growing capabilities in developing next-generation space technology.
