China tests quantum direct communication tech in space launch

China has moved closer to building a quantum communication network that links space, air and ground after a successful rocket test of new quantum technology, the Beijing Academy of Quantum Information Sciences (BAQIS) announced recently.

A test rocket called Yuanxingzhe-1, developed by Beijing-based company Space Epoch, completed its first sea-based recovery flight on May 29.

The rocket carried two small devices: a quantum direct communication laser module and a phase encoding module, both developed by the academy's research team.

Long Guilv, vice president of BAQIS and a professor at Tsinghua University, said these modules are critical for sending and receiving information.

Unlike traditional secure communication, which uses two channels, quantum direct communication uses only one channel. This allows information to be sent directly while also detecting and preventing eavesdropping, making the system more secure but also harder to build.

Quantum technology faces many challenges in space, such as strong forces during launch and changes in temperature and radiation. However, Long said Beijing's commercial aerospace growth provides opportunities to improve designs and lower costs, for instance, by optimizing mechanical design for vibration resistance or adding aluminum plates for radiation protection.

During the recent test, the equipment was launched to a height of about 2.5 kilometers, a stage with the strongest forces and vibrations. Later checks showed that both devices worked as expected. The team plans more tests using current technology to speed up the development of China's space-to-ground quantum communication network.

Over nearly three years, the system was reduced in size from five desktop computers to just one, meeting the requirements for space launches. Long said he hopes to send the payload into space within two years.

The technology is expected to improve secure communication in high-security fields such as government, finance and energy, marking the start of a "quantum-plus" era for information security.