A cold atomic clock has only lost the accuracy equal to one second in 30 million years during two years in orbit on China’s space lab Tiangong-2, according to the Chinese Academy of Sciences (CAS), People’s Daily Online reported on July 26.

The clock is more accurate than most atomic clocks. It is expected to make GPS systems more capable and precise once it’s applied to this technology.

It took over 10 years for scientists from Shanghai Institute of Optics and Fine Mechanics to finally operate the cold atomic clock in space, which was a world first.

They have solved key issues including the physical system of the cold atomic clock in a microgravity environment, the preparation of cold atoms for long-term autonomous operation and the manipulation of laser optical system.

The achievement was published in the international academic journal Nature Communications on July 24, 2018. It is regarded as a milestone in the development of space-based cold atomic clock sensors.

The clock, launched into space together with the Tiangong 2 space lab on September 25, 2016, is the world’s first cold atomic clock that works in space, and has completed all scheduled scientific goals.