The Shenzhou 16 spacecraft lifted off from the Jiuquan launch centre on the edge of the Gobi Desert in north-western China atop a Long March 2-F rocket.
The crew, including China's first civilian astronaut, will overlap briefly with three astronauts currently aboard the Tiangong station, who will then return to Earth after completing their six-month mission.
A third module was added to the station in November, and Chinese space programme officials said on Monday (29 May) that they have plans to expand it, along with launching a crewed mission to the Moon before 2030.
China built its own space station after it was excluded from the International Space Station, largely due to US concerns over the Chinese space programme's intimate ties with the People's Liberation Army, the military branch of the ruling Communist Party.
China's first manned space mission in 2003 made it the third country after the former Soviet Union and the US to put a person into space under its own resources.
On this latest mission, payload expert Gui Haichao, a professor at Beijing's top aerospace research institute, will join mission commander Jing Haipeng, who is making his fourth flight to space, and spacecraft engineer Zhu Yangzhu.
The crew will stay aboard the station for about five months, during which they will conduct scientific experiments and regular maintenance.
The mission comes against the background of a rivalry with the US for reaching new milestones in space. The latter's spending, supply chains and capabilities are believed to give it a significant edge over China, at least for now.
China has broken out in some areas, however, bringing samples back from the lunar surface for the first time in decades and landing a rover – Jade Rabbit – on the less-explored far side of the Moon.
The US, meanwhile, aims to put astronauts back on the lunar surface by the end of 2025 as part of a renewed commitment to crewed missions, aided by private sector players such as SpaceX and Blue Origin.
The two countries have also separately landed rovers on Mars and China plans to follow the US in landing a spacecraft on an asteroid.
Space is becoming an increasingly competitive place. Last week, Virgin Orbit became a casualty of the fight, announcing that it would be permanently ceasing all operations and selling off its satellite-launching assets at auction.
On the upside for the furtherance of space exploration, the UK government announced a £50m fund to support the development of cutting-edge research and development facilities last week.
Saudi Arabia is also keen to get in on the space action, with researcher Rayyanah Barnawi one of the passengers in the recent private flight to the International Space Station – the first female Arab astronaut. Barnawi was accompanied by fellow Saudi mission specialist Ali Alqarni, the second male astronaut from the Gulf kingdom to go to space. The pair were the first Saudis to travel in a rocket since a Saudi prince flew aboard the space shuttle Discovery in 1985.
Marginally closer to home, the concept of space tourism is another aspect of mankind's intergalactic pursuits. Virgin Galactic (unaffected by the closure of Virgin Orbit) recently completed what could be its final spaceflight test before the company starts commercial operations ferrying paying passengers on short space journeys. Despite Virgin Galactic's spaceplane approach being considerably cheaper than such rivals as Jeff Bezos' Blue Origin rocket-fuelled launches, the high price of a ticket still means that it will be mostly millionaires going into space for the foreseeable future.
