Chinese space authorities require the plane to be reused more than 100 times and have fewer than three failures per 1,000 flights, according to Song’s team in a paper published in Astronautical Systems Engineering Technology journal last month.

These goals were set after evaluation of the pace of China’s technological progress and international advances “pioneered by SpaceX”, said Song and his colleagues.

China’s Long March rockets are among the least expensive methods of accessing space and they have played an important role in the rapid expansion of China’s space infrastructure in recent years.

The average cost of a Long March rocket is about US$3,000 per kilogram of cargo lifted to the lower-Earth orbit, according to a CASC report published in the journal Aerospace China in August. In comparison, Nasa’s space shuttles cost more than US$60,000 per kilogram lifted.

But in recent years SpaceX, using its reusable Falcon 9 rockets, has slashed its launch cost to about the same as that of the Long March rockets, according to CASC.

SpaceX founder Elon Musk said Starship Super Heavy – the largest ever reusable rocket ever that is being readied for its first flight this month – can reduce the cost to US$10 per kilogram.

Although Musk’s claim was doubted by many critics, it is widely believed SpaceX could bring the cost down to a few hundred dollars per kilogram.

With an aim of bringing the payload cost down to about US$150 dollars per kilogram, the Chinese space plane is likely to remain competitive as the space race moves to a new, more intense stage, according to Song’s team.

China conducted two test flights of the new transport system in the Gobi Desert, the researchers said.

In July 2021, a space plane blasted off vertically from a rocket launch pad, made a suborbital flight in space and touched down at a military airport.

The same hypersonic vessel was launched again in August last year and returned unscratched, proving the reusable design was feasible.

But the tested plane was smaller than the final version, which still needs years of development to enter commercial service, according to Song’s team.

The new transport system will be much more complex than the single-use Long March rockets.

For instance, rocket engines would be used in missions with a large payload but air-breathing engines would carry lighter cargoes, and the space plane must work efficiently with the two vastly different power sources, Song and his team said.

The plane also needs to work in a wide speed range in environments varying from sea level to space.

Artificial intelligence is playing an increasingly vital role in designing the optimal plane because it can quickly and effectively solve complex engineering issues based on a small number of test flights, Song’s team said.

China plans to launch nearly 13,000 internet satellites to counter SpaceX’s Starlink. It also plans to build other mega infrastructures, such as a space solar power plant that requires low-cost launch services on a massive scale.

The Chinese space transport system must be capable of conducting more than 1,000 flights and carry over 10,000 passengers to space each year by 2045, according to a plan by Chinese space authorities.

But even though the cost of China’s space launches may be low, few other countries are using China’s services, mainly because of a US sanction that bans any satellites that employ American technology or components from being launched in China.