China has achieved two-way laser communication between the Earth and the Moon, making it the second nation after the United States to do so. But the data rates it achieved were far behind those recorded by NASA more than a decade ago, and that has left space experts scratching their heads. Using telescopes in Yunnan province and an experimental satellite that is now orbiting the moon after a launch accident in 2024, the team recorded a downlink speed of 100 megabits per second and an uplink speed of 1.25 Mbps, according to the Chinese Academy of Sciences, which led the project. The 2013 lunar laser communications demonstration achieved download speeds of 622 Mbps and upload speeds of 20 Mbps, approximately six times faster for downloads and 16 times faster for uploads. Jonathan McDowell, a London-based space historian and former Harvard astronomer, said the Chinese and American experiments were comparable. The laser communications expert and head of the research team highlighted the laser’s speed advantage compared to other methods in an interview with state news agency Xinhua last week.
