China's relay satellites facilitate clear, smooth space-ground communication

BEIJING, June 24 (Xinhua) -- A space-based measurement and control system composed of multiple relay satellites has guaranteed clear and smooth communication between ground control and Chinese astronauts in space.

The relay satellites Tianlian I-03, Tianlian I-04 and Tianlian II-01 have been providing stable measurement and data relay support for the complex consisting of Tianhe core module, the cargo craft Tianzhou-2 and the Shenzhou-12 spaceship, according to the Beijing Space Information Transmission Center.

"It is the first time China's independently developed Tianlian II-01 relay satellite has served one of the country's manned space missions," said Zheng Yonghui, general engineer of the center, adding that the satellite accelerates video and audio transmission to achieve both improved call quality and longer duration.

Engineers at the center developed the voice and image analysis software and timed alert software to improve the stability and reliability of communication.

The Shenzhou-12 spaceship was launched atop a Long March-2F carrier rocket on June 17. The three Chinese astronauts aboard Shenzhou-12 entered the core module Tianhe after the spaceship conducted a fast autonomous rendezvous and docking with Tianhe the same day.

Tianhe was sent into orbit on April 29, and the cargo craft Tianzhou-2 was launched on May 29.