An experiment satellite was brought to China Space Station via the Wednesday-launched Tianzhou-6 cargo spacecraft, the satellite's developer, Dalian University of Technology, said.

The satellite, dubbed Dalian-1, is a high-resolution Earth remote sensing CubeSat and weighs 17 kilograms. On the night of May 10, remote sensing data sent back from Tianzhou-6 showed that the satellite was functioning normally.

Prior to the launch, Dalian-1 was installed outside the spacecraft's ultralight multiple satellites deployer – a payload capable of releasing the satellite directly from Tianzhou-6 and is one of the satellite's technologies awaiting verification.

Others include high-resolution remote sensing imaging, an OpenHarmony operating system using China's domestically developed processing chip, and advanced satellite components.

"The main payload of the satellite is a high-resolution multispectral camera, capable of achieving low-cost sub-meter high-resolution observation on ocean and Earth in orbit," said Xia Guangqing from the university, who is also the chief designer of the satellite.

Unlike the toxic hydrazine propellant used in traditional satellites' propulsion systems, this satellite uses a hydroxylammonium nitrate mono-element module propulsion system. The pre-packaged propellant features green, non-toxic, high power, and low energy consumption, significantly improving the micro-nano satellite's in-orbit rapid maneuvering capabilities.

The satellite will be released at an appropriate time following the Tianzhou-6 cargo craft's docking with the space station.

Read more: China's Tianzhou-6 cargo spacecraft docks with China Space Station

China's in-orbit release mechanism

In fact, China had already launched several satellites from orbiting spacecraft, one of them as far back as 2009. 

On October 30, 2009, an accompanying satellite was launched from the Shenzhou-7 manned spacecraft, making China the third country in the world to master in-orbit spacecraft release and maneuver technologies.

On September 15, 2016, China's space lab prototype Tiangong-2 released an accompanying satellite that also functioned as a "selfie camera" in space.

Last year on December 18, a 12-kg test satellite, also known as the Macao Student Science Satellite 1, was released from a deployer on the Tianzhou-5 cargo ship.

In addition, the Mengtian lab module at China's space station is also capable of releasing micro-spacecraft and satellites into space through the in-orbit release mechanism.

The mechanism can deploy micro-spacecraft and CubeSats of up to 100 kilograms into orbit and is the first of its kind loaded on the China Space Station.

Compared with launching and deploying satellites by rockets, doing so through a space station is safer, cost-efficient and has better utilization of the station, said Yang Yuguang, the vice chair of the Space Transportation Committee of the International Astronautical Federation.

Launching satellites via the lab module involves several steps. First, the satellites are loaded inside the Tianzhou cargo spacecraft that can be launched and docked with China's space station. Then, astronauts and scientists aboard the space station would perform a check on the satellites before releasing them through the mechanism.

"It serves as an extra test in orbit and makes sure the satellites are intact," Yang told CGTN in an interview last year.

Similar to sending a payload outside the cabin, the satellites will be packed as an entire cube and transported to the airlock cabin, or the payload cabin, to be grasped by the robotic arm when released in a safe direction.