But its role as the sole venue for a continuous human presence in space, scientific research and a testing ground for future space exploration is coming to a close, potentially signaling an end to an unparalleled era of global cooperation in space.
China, whose astronauts have always been excluded from the ISS, successfully launched the first module of its planned space station on Thursday morning from the Wenchang launch site in the southern island of Hainan, according to the China National Space Administration.
"The Tianhe, or Heavenly Harmony", module blasted into space atop a Long March 5B rocket from the Wenchang Launch Center on the southern island province of Hainan, marking another major advance for the country's space exploration program that has chalked up a series of accomplishments in recent months.
"We did not intend to compete with the ISS in terms of scale", Gu Yidong, chief scientist of the China Manned Space program, was quoted as saying by Scientific American.
The lab disintegrated on re-entry into the Earth's atmosphere in 2018, two years after it ceased functioning.
Tiangong will operate in a low-Earth orbit at an altitude of 340 km to 450 km, Xinhua said in a report on Thursday.
The completed station, weighing little more than 90 tons, will be around a quarter the size of the International Space Station.
DrPreparations for the launch of the Chinese "Long March 5B" missile, together with the basic unit to build the "Tiangong" (Sky Palace) space station, are in full swing.
September 15, 2016: Tiangong-2 was launched.
The China National Space Administration has already invited scientists around the world to participate in the mission and four payloads developed by scientists from France, Italy, Sweden, Russia and China have been preliminarily selected.
The facility, planned for either the surface or the orbit of the Moon, would house experimental research facilities and would be Beijing's biggest global space cooperation project to date.
The next piloted Shenzhou flight, and the first expected to dock with the Tianhe module launched on Wednesday, reportedly could fly as early as June, although Chinese space officials have not yet identified the crew or specified a launch date.
It put the first Chinese "taikonaut" in space in 2003 and landed the Chang'e-4 robot on the far side of the Moon in 2019 - a historic first.
It took more than a decade, but in 1970, China launched its first satellite on a Long March rocket.
The habitable space inside the core module is about 50 cubic meters. It was largely banned from the International Space Station due to United States objections to the secretive nature of the Chinese program and its close military ties.
In 2016, China launched its second orbital lab, the Tiangong-2.
Under President Xi Jinping, plans for China's "space dream", as he calls it, have been put into overdrive.
"China, in a sense, is trying to catch up with capabilities that other space powers that have already done", says space analyst Laura Forczyk, per NewScientist.
China's unmanned moon mission in December carried rocks and soil sample back to Earth, making it the third country after the USA and Russian Federation to carry out this feat. It has been gathering data in its orbit on Mars since February and will explore the Red Planet's surface.
But lunar work was dealt a setback in 2017 when the Long March-5 Y2, a powerful heavy-lift rocket, failed to launch on a mission to send communication satellites into orbit.
China hopes to ultimately land the rover in May in Utopia, a massive impact basin on Mars.