By Kurtis Archer and AFP | 2025-01-06

The International Space Station (ISS) has been an orbital laboratory providing Earth with various areas of scientific knowledge since 1998.

Before its construction, the United States had plans for its own space station, and Russia had inherited Mir from the Soviet Union while planning other projects.

But the two nations combined their space station goals and integrated their modules to form the ISS, which still flies today and has kept a constant human presence in space for over two decades.

The United States, Japan, Canada and participating countries of the European Space Agency have committed to operate the microgravity lab through 2030 -- though Russia, the fifth partner, has committed to operations only through 2028.

The station is in its last decade of life, and NASA has considered options for its ultimate decommissioning.

Disassembly of the station with return of components to Earth would be far too expensive and extensive a project, deemed unworthy of pursuit because of the logistical challenges.

Boosting the station to a higher orbit would extend its lifetime and preserve the station hardware for future generations, but NASA does not have the technology to serve crew or handle cargo at higher elevations. Plus, the risk of debris collisions increases drastically above 413.6km.

The station is too large for an uncontrolled deorbit to occur safely, so the ISS is set to be deorbited in a controlled fashion and laid to rest at Point Nemo in early 2031, after 33 years of service.

Judging from past observations of how other stations such as Mir and Skylab disintegrated on atmospheric re-entry, NASA engineers expect the orbital outpost to break up in three stages.

First, the massive solar arrays and the radiators that keep the orbital lab cool will come off, then individual modules will break off from the truss, or the station's backbone structure. Finally, the truss and the modules themselves will come apart.

Much of the material will be vaporized, but NASA expects large pieces to survive. For this reason, NASA is aiming for an area of the Pacific Ocean called Point Nemo, one of the most remote areas of the world and known as the graveyard of satellites and spaceships.

Hundreds of spacecraft have been buried at Point Nemo for more than a half-century.

Future technology

Last June, NASA announced that it had selected private corporation SpaceX to develop the US Deorbit Vehicle (USDV) to bring down the space station.

The USDV will be designed to break apart and burn up in the atmosphere alongside the ISS, with any surviving pieces being buried in the ocean with the station's remains.

Weighing 430,000kg, the ISS is by far the largest object built in space. The USDV will be needed to guide its descent and destruction properly without posing a threat to life forms on Earth.

NASA Commercial Space Division Director Phil McCalister spoke of the outdated station on National Public Radio's Morning Edition last February.

"I kind of see this as like an automobile. When we bought that automobile in 1999, it was state of the art. And it has been great. And it serves us well and continues to be safe. But it's getting older. It's getting harder to find spare parts. The maintenance for that is becoming a larger issue," he said.

ISS Director Robyn Gatens echoed McCalister's sentiment.

"We say the International Space Station has a lot of capability, but it's more like a test kitchen," she told NPR. "I'm looking forward to seeing the future commercial space stations take these laboratory capabilities and really develop them into state-of-the-art space laboratories."

Though some environmentalists worry about the implications of the spacecraft cemetery in Earth's waters, space hardware resting on the bottom around Point Nemo has proven scant and harmless compared to virtually all other forms of ocean pollution.

Much more serious than oceanic concerns and not yet fully understood are the consequences of launches and reentries for Earth's upper atmosphere.

Still, NASA concludes that consigning the ISS to Point Nemo will not pose any serious long-term consequences for the safety of Earth's environment. Given the alternatives, controlled deorbiting to the ocean is the safest choice.

NASA's future plans include exploring deep space by using new stations with modern technology built and operated by private companies.