China has recently conducted an in-orbit test of a robotic cargo spacecraft to deploy miniature satellites, according to a project insider.

In the test that took place on Nov 14, the Tianzhou 4 cargo ship, which was on its journey back to Earth, deployed a CubeSat named SmartSat 3A into a low-Earth orbit about 380 kilometers above the ground, said Liu Likun, founder and CEO of Smart Satellite, a private satellite maker in Beijing that built the SmartSat 3A.

The minisatellite was accurately placed in its preset orbit and soon established a data link with ground control. It has started carrying out its tasks, he said.

According to Liu, the test was intended to verify the Tianzhou cargo ship model's capability of deploying small satellites.

"Our CubeSat is equipped with a wide-field camera and space environmental sensors and is tasked with taking pictures of target zones and performing in-orbit tests for the optimization of space technologies. It will also be used to serve educational purposes like promoting space knowledge," Liu said, adding that the craft is expected to work in orbit for around a year, depending on the orbital environment surrounding it.

A CubeSat is a type of miniaturized satellite made up of multiple cubic units, and is often used by commercial satellite companies and research entities to conduct simple scientific experiments or technological tests that do not need large, sophisticated satellites. To date, more than 1,000 such craft have been launched around the world to serve purposes in education, atmospheric surveying, technology demonstrations and space exploration.

Launched on May 10 from the Wenchang Space Launch Center in Hainan province, Tianzhou 4 docked with Tiangong in a low-Earth orbit of around 400 km later that day.

Tianzhou 4 was the third cargo ship to have linked with the Tiangong space station, following the Tianzhou 2 and 3.

Carrying nearly 6 metric tons of propellants and materials, including more than 200 packages, the craft was tasked with supporting the Shenzhou XIV mission, during which a three-member crew is scheduled to stay six months inside the Tiangong station.

The Shenzhou XIV crew has spent more than five months on board the space station.

Tianzhou 4 departed from the Tiangong station on Nov 9 and then conducted some space technology tests before falling back to Earth on Nov 15, according to the China Manned Space Agency.