A refueling aircraft, known as a space oil tank truck, made its debut at Airshow China 2021 in Zhuhai, South China's Guangdong Province, which kicked off on Tuesday. The aircraft can provide an energy guarantee for the long-term operation of satellites in orbit. 

Satellites have become vital for modern human life. They provide weather forecasts, television broadcasts, mobile communications, global navigation and other services. 

However, it is very expensive to build a geostationary orbit satellite, usually costing billions of yuan. When the fuel runs out, the satellite's life is over. Therefore, fuel replenishment technology can provide an energy guarantee for the long-term operation of satellites in orbit.

A fuel replenishment aircraft was designed as a result, leading to its debut at this year's Airshow China. 

The aircraft was developed by Shanghai Academy of Spaceflight Technology and can load as much fuel as possible while maintaining basic in-orbit operations, Science and Technology Daily reported, citing a designer from the academy. 

The designer said 50 kilograms of fuel could help extend the life of a satellite by one year. The refueling aircraft can carry 1.3 tons of fuel at a time, more than half of its total weight. It can cut costs by 35 percent compared with re-launching a satellite.

The aircraft is equipped with an automatic driving function. When a satellite sends a message asking for help, the aircraft can autonomously track and approach the satellite using navigation systems. When it reaches within about 2 meters of the satellite, it will be connected to the refueling port to deliver fuel.

The docking replenishment device, which made its debut together with the new aircraft, is a key technology for the in-orbit replenishment mission and is the first of its kind in China. It can create conditions for the refueling aircraft through close and reliable connection with the satellite. 

In 2017, the Tianzhou-1 cargo spacecraft successfully docked with the Tiangong-2 space laboratory, completing the first in-orbit propellant refueling test. It means China has made a breakthrough in in-orbit refueling technology, becoming the third country in the world after the US and Russia to independently master this technology.