A Chinese satellite achieved a milestone that is making noise in the world of space telecommunications: it transmitted data at a speed of 1 Gbps using a laser of only 2 watts from an altitude of about 36,000 kilometers. This experiment, led by researchers from Peking University and the Chinese Academy of Sciences, marked a dramatic difference compared to what Starlink, SpaceX's satellite internet service, offers today. To give you an idea, Starlink operates at just 550 km altitude and typically offers speeds between 100 and 200 Mbps, so the comparison is not insignificant.

The most impressive thing is that the laser, with such low power, managed to maintain a solid and stable connection through the Earth's atmosphere, which is always an obstacle due to turbulence and optical distortion. But here, China relied not only on laser power, but also on advanced technologies that allowed the signal to remain sharp. The result: a data rate that dwarfs many terrestrial and satellite systems.

AO-MDR Innovation to Overcome Atmospheric Turbulence

How did they achieve this? The key lies in a technological combination dubbed AO-MDR, which combines two techniques: adaptive optics (AO) and mode diversity reception (MDR). The former allows for the correction of laser beam distortions caused by the atmosphere in real time. The latter, on the other hand, is responsible for capturing the largest possible number of signals, even those that arrive slightly distorted or out of phase, in order to reconstruct the original message with the greatest fidelity.

But they didn't stop there. The system also employed algorithms that analyzed eight different signal paths and selected the three most coherent ones to maintain the best possible transmission quality. This technique significantly increased the proportion of useful data transmitted, rising from 72% to 91%. In an environment as harsh as space, that kind of efficiency is crucial.

This entire system was tested between the satellite and a ground station in China, demonstrating that optical space communications can be much more effective than current radio frequency-based methods. Less interference, more security, and breakneck speeds, all with ridiculously low power consumption by space standards.

This test carried out by China demonstrates that the future of space communications lies in lasers. Not only because of the speed, but also because of the ability to send information without relying on saturated radio frequency bands, and because of the difficulty of intercepting laser signals, which makes them much more secure. If this technology becomes popular, we could see a radical change in how the world connects from space. China has just taken a giant step in that direction.