The Long March-2F carrier rocket carrying China's Shenzhou-11 manned spacecraft blasts off from the launch pad at the Jiuquan Satellite Launch Center in Jiuquan, northwest China's Gansu Province, Oct. 17, 2016.File photo:Xinhua

After flying in orbit for two days, China's reusable spacecraft landed safely to its designated site on Sunday, marking a breakthrough in China's technology for reusing spacecraft.

So far, Chinese space authorities have been virtually silent on details of the experimental flight. All that can be learned from reports by the Xinhua News Agency is that the spacecraft was successfully launched on Friday from the Jiuquan Satellite Launch Center, which has witnessed multiple milestone events in the country's manned space exploration, and the carrier rocket is the Long March-2F, the "go-to" launch vehicle for China's manned space projects. 

No official renders or photos of the spacecraft have been made public as of press time. Xinhua pointed out on Sunday that the successful experiment of the spacecraft offers more convenient solutions for future peaceful use of the space and enables cheaper round-trips.

The two-day flight experiment was designed to test the performance of new materials for the reusable vehicle and to test the monitor and control system, Song Zhongping, a military expert and TV commentator, told the Global Times on Sunday.

"The test would focus on the vehicle's capability to enter orbit via a carrier rocket launch and the reliability of its returning to Earth, which are key for a reusable orbital vehicle," said Wang Ya'nan, chief editor of Beijing-based Aerospace Knowledge magazine.

China has not developed this kind of reusable orbital vehicle before, and once it achieves maturity and puts into practical use, it will transform the current space use landscape in both civilian and military use, experts said. 

"The vehicle could be equipped with robotic arms to conduct maintenance and supply missions for on-orbit spacecraft such as satellites. And in return, Chinese satellites could enter a new age of modularization, further tap into the potential of space application," Wang said.

Despite keeping a low profile, the news of reusable spacecraft has gained a great deal of attention and led to wild speculation, with many, such as space.com, the New York-based source of space news, believing that the flight mission was related to China's space plane project.

The US website cited a Xinhua report in October 2017, quoting Chen Hongbo, a researcher with China's state-owned space giant China Aerospace Science and Technology Corp, as saying that China plans to launch its reusable spacecraft in 2020. 

"Unlike traditional one-off spacecraft, the new spacecraft will fly into the sky like an aircraft," Chen revealed, adding that the spacecraft can transport people or payloads into the orbit and return to Earth. The spacecraft will also be easier to maintain and can increase the frequency of launches at lower cost, bringing new opportunities for more people to travel into space.

China has been developing its own reusable Earth-to-orbit space vehicles that can take off and land horizontally, and has already completed several crucial ground tests for engines and other key components [of the reusable spacecraft,] Liu Shiquan, a vice director of the China Aerospace Science and Industry Corp, told media at the Global Space Exploration Conference in Beijing, the  People's Daily reported.

Many foreign reports and Chinese netizens have been drawing comparisons between the mysterious vehicle, if it is a fixed wing space plane, and the X-37B space plane owned by the US Air Force.

The US model has flown a total of five orbital missions. The first X-37B flight was launched in 2010, while the fifth mission began in September 2017 and is still underway, space.com reported on Friday.

Based on materials provided by the China Academy of Launch Vehicles, the developer of the Long March-2F rocket, the 58.4-meter-long launch vehicle with 3.35-meter-diameter core stages is capable of sending payloads weighing 8.6 tons into Low Earth orbit.

The Long March-2F, which has a unique escape design on the top-end, is also the go-to launch vehicle for China's manned space programs. As of June 2017, the Long March-2F had made 13 successful flights, sending six manned spaceships, five unmanned spaceships, two space labs and 11 Chinese astronauts into space.

The use of Long March-2F for the mission shows that the experiment mission is of great significance, Xi Yazhou, a military expert, said in his column published by Guancha.com on Friday.

Xi also cited unknown sources as saying that the Long March-2F has installed a 5-meter-diameter nose cone for the special mission, and noted that if this information is true, it would mean that the vehicle could be "larger than a conventional spacecraft." 

Xi found Chinese netizens' small-sized space plane theory very possible. 

Considering the data and method of launch, China's orbital vehicle could be very similar to US' X-37B, and the vehicle could have a fixed wing span of more than four meters, Wang said. 

It is too early to determine when the Chinese orbital vehicle could be put into practical use, as the project has only just had its first launch and return test, Wang said, noting that once the technology matures, China would be the third country to have such space planes, following the US and Russia.

NASA's now-retired space shuttle fleet flew 135 missions between 1981 and 2011, and a similar vehicle built by former Soviet Union, called Buran, made it to orbit once, in 1988, space. com said.

The reusable orbital spacecraft would be first used in civilian domains, conducting operations such as surveying the Earth, monitoring the environment and maintenance for in-orbit satellites, space experts said.

China's authorities have not revealed any intention of military use for the vehicle, but observers stressed that just as the US Air Force's X-37B claimed to have the capability to strike anywhere on Earth within half an hour, China should at least have that capability.