China's space program just took another leap forward, with the successful launch of the nation's second experimental space laboratory – called Tiangong–2.
While Tiangong–2 is only a tiny prototype module – measuring about 10 metres long and weighing just 8.6 tonnes – it has the functionality of a working space station, albeit miniaturised, and will help China prepare for a larger, permanent station that's expected to be built around 2022.
"By itself, Tiangong 2 is not a monumental achievement, but it is an important step in a larger effort to eventually build a Chinese space station in the early 2020s," space expert Brian Weeden from the Secure World Foundation in Washington DC told Davide Castelvecchi at Nature.
The launch took place shortly after 10pm local time on Thursday at the Jiuquan Satellite Launch Centre in China's Gobi Desert, with the space lab hitching a ride on a Long March–2F T2 rocket.
About 10 minutes after lift-off, the module detached from the rocket after reaching an orbit altitude.
Once some initial testing of the module's systems is complete, the uncrewed mini station will manoeuvre itself to an altitude of about 393 kilometres – about the same height above Earth as the International Space Station – where it will be stationed for the next two years.
Then, in mid-to-late October, the module will receive its first crew, with two Chinese astronauts aboard China's Shenzhou–11 spacecraft expected to dock with the station. The astronauts are expected to work in the lab's close quarters for 30 days, testing equipment and running experiments, before returning to Earth.
For Tiangong–2's crew, one of the challenges will be in carrying out their research in such close quarters.
"Tiangong–2 is hardly the size of a palace," China's state-run media agency Xinhua reports. "But its name means heavenly palace in Chinese, and it symbolises the dream that the Chinese have long envisioned in the sky."
The scientists will conduct studies in aerospace medicine, space physics, atmospheric monitoring, plant cultivation, and solar storm research, among other things. The space lab is also equipped with an atomic clock, designed to investigate fluctuations in microgravity.
"The number of experiments carried out by Tiangong–2 will be the highest of any manned space mission so far," researcher Lyu Congmin from the Chinese Academy of Sciences told Xinhua.
The prototype lab follows on the heels of its predecessor, Tiangong–1. The first module launched five years ago, and was mostly used to fine-tune things like docking mechanisms and operational processes, whereas Tiangong–2 has more of a strict research focus.
In April next year, China's first space cargo ship, Tianzhou–1, will dock with Tiangong–2, and top up its fuel and other supplies for anticipated future crew stays. After two years, it's expected that the module will be deactivated, and brought to rest somewhere in the Pacific Ocean.
By that time, China will be look at building and deploying a more ambitious follow-up to Tiangong–2. Once the Tiangong program is complete, a space station designed to orbit Earth on a more permanent basis will be assembled, with an expected 10-year mission time-frame.
While details on this station are thin on the ground, it's likely to consist of three parts – a core module, attached to two separate space labs, much like the Tiangong craft. It's expected to be able to host astronauts on long-term stays lasting up to a year.
"[Tiangong–2 is] a reminder that China has a manned space program, including the ability to put its own astronauts into space, something the Americans cannot do," Chinese space policy expert Dean Cheng from the US Heritage Foundation told Rebecca Boyle at New Scientist.
That's because Russia currently ferries US astronauts into space, although in the long term, it's a job that private companies like SpaceX and Boeing are vying for. But getting the infrastructure and technology up to speed isn't an easy task, as SpaceX's recent rocket explosion clearly proves.
In the meantime, the impressive self-sufficiency of China's space program is something for the rest of the world to take note of, and in addition to furthering the nation's scientific aims, it might give China something else that the nation may crave.
"China wants to build and operate a space station for the same reasons the United States and Soviet Union did in decades past," Weeden told Nature. "Prestige."