China ushers in construction of space station era
China’s latest state-of-the-art carrier rocket, the Long March-5B, made a successful maiden flight on Tuesday, during which the new rocket managed to send the assembly of a trial version of the country’s new-generation manned spaceship with no crew and a testing cargo-returning spacecraft into planned orbit.
The successful launch signaled that a new era of the construction of China’s manned space projects including space stations has been officially ushered in, according to rocket developer and space industry insiders.
The 53.66-meter-long Long March-5B, with a diameter of 5 meters for its core, took off from the Wenchang Space Launch Center, South China’s Hainan Province on Tuesday. After a flight of 488 seconds, the payloads separated from the rocket’s body, and went into designated orbit.
“The successful maiden flight of the Long March-5B, a new type of launch vehicle that has been specially developed for China’s manned space projects, marked the era of construction of a Chinese space station officially dawning,” Wang Jue, chief commander of the Long March-5B rocket, told the Global Times on Tuesday.
The Central Committee of the Communist Party of China, the State Council, and the Central Military Commission extended congratulations on the successful maiden flight of the Long March-5B on Tuesday.
The rocket also made key breakthroughs including achieving a ‘zero window launch’ – a term to describe extremely high, second-level accuracy of the launch procedure, and high thrust orbiting technology, said Li Dong, chief designer of the Long March-5 rocket.
Such key technological breakthroughs are exclusively relevant to the imminent construction of the space station, Li explained.
Ji Qiming, an official with China’s Manned Space Agency, revealed at a Tuesday press conference after the successful launching that China eyes to complete the construction of its space station by roughly 2022 which includes 12 flight missions.
One-and-a-half stage
The Long March-5B carrier rocket with one core stage and four boosters – which is known as a half stage – makes it the first heavy-lift rocket with liquid rocket propellant that has adopted such a one-and-half stage into orbit technology in China, according to a statement from the rocket developer, the China Academy of Launch Vehicle Technology (CALT), of the China Aerospace Science and Technology Corporation, sent to the Global Times on Tuesday.
Such a one-and-a-half stage mode would remarkably increase the rocket system’s reliability as the fewer the stages, the simpler the system would be. And the reduced time of stage separation also lowers the chance of malfunctions.
Pang Zhihao, a Beijingbased space expert, told the Global Times that the maiden flight of the Long March-5B would fill in a blank space in China’s carrier rocket category, and declared that China has entered the world’s first-class league in terms of large LowEarth Orbit (LEO) carrier rocket technology capabilities.
The new rocket, using fuels such as liquid hydrogen, liquid oxygen and kerosene, weighed 849 tons at launch and has a take-off thrust of around 1,078 tons, enabling it to carry payloads no less than 22 tons into LEO, according to CALT.
Similar in appearance
The Long March-5B is a smaller variant of the Long March-5. Both rockets belong to the Long March-5 launch vehicle series as they have a similar chubby appearance.
Observers are able to tell the difference between the two brother models of the Long March-5 series by simply looking at the size of their payload fairing and the nose cone on the top of a rocket to protect it against impact pressure and heating during launch through the atmosphere.
Long March-5B possesses the largest payload fairing among all Chinese carrier rockets to date, with a height of 20.5 meters – as tall as a six-story building – and a diameter of 5.2 meters, which, according to the CALT, is customized for the spaceship’s launch mission.
Two Long March-5 models vary significantly in the type of services they are supposed to provide. The Long March-5 is mainly used to send large-scale satellites, as well as deep space explorers such as the Chang’e-5 lunar probe and Mars probes, into high Earth orbit, whereas the Long March-5B is the goto type for launch missions for spacecraft such as modules of the future space station into LEO.
‘Three warriors’
By the completion of the Long March-5B’s maiden flight, all three types of carrier rockets, dubbed the “three warriors” that are commissioned specially for China’s manned space projects, are now ready in place. The three carrier rockets in this series are the Long March-2F, the Long March-7 and the Long March-5B.
Jing Muchun, chief commander of the Long March2F, told the Global Times that in the past two decades, the Long March-2F has sent five unmanned, six manned spaceships and two space labs into space with a 100 percent success rate.
The 13 successful Long March-2F missions include one sending Yang Liwei, China’s first astronaut, into space in 2003.
The Long March-7 is known as the “charted train” for space cargo with a launch capability of 13.5 tons into LEO, and 5.5 tons into 700-kilometer-solar synchronous orbit.