It sounds like the beginning of a work of science fiction, but it is a quiet milestone in the history of our species. On Tuesday, October 31, 2000 marked the last day in which every human being on the planet was on this side of the atmosphere. Since then, there has not been a single moment in which all of humanity has been confined to our home planet.
A historic launch. That October 31, 2000, A Soyuz spacecraft took off from the Baikonur Cosmodromein Kazakhstan, carrying Expedition 1 of the International Space Station on board: American commander Bill Shepherd of NASA and Russian cosmonauts Sergei Krikalev and Yuri Gidzenko of Roscosmos.
The crew arrived at a fledgling ISS on November 2, 2000. It only had a couple of modules (the Russian Zarya and the American Unity, assembled in 1998), but since then, the orbital laboratory has been occupied continuously. For 24 and a half years, there is always a human floating about 400 kilometers above our heads.
A quarter of a century. The International Space Station is a collaborative project between five space agencies (the American NASA, the Russian Roscosmos, the European ESA, the Japanese JAXA and the Canadian CSA). It is not only a symbol of international cooperation, but an unparalleled scientific laboratory, which orbits the Earth every 90 minutes at a speed of almost 28,000 km/h.
In this quarter of a century, the orbital station has reached a habitable volume greater than that of a six-bedroom house, with a wingspan of 109 meters and an average of seven people always on board. It can dock up to eight spacecraft simultaneously and has hosted almost 3,000 investigations from more than 108 countries, taking advantage of microgravity to study everything from particle physics to the effects of space travel on the human body.
The ISS passes the baton. Aged and with age-related ailmentslike the air leaks that cause headaches for its operators, the ISS partners plan to abandon it in 2030, before a ship developed by SpaceX tow it to a safe place for atmospheric reentry.
NASA’s strategy is clear: move from being the primary owner and operator to becoming a key customer, thus ensuring continued human presence in low-Earth orbit. This will allow further research in microgravity (which is crucial for future missions to the Moon and Mars), maintain international collaboration and foster a commercial space economy.
USA announced last year its intention to reduce the budget allocated to the ISS hoping for a quick transition to new commercial space stations. Companies like Axiom Space (with its Axiom Sation project), Blue Origin (with its Orbital Reef) or Voyager Space (with Starlab, in collaboration with Airbus) are developing new private orbital platforms.
What if they are not ready on time? If commercial stations do not arrive by 2030, humanity will continue to inhabit low orbit thanks to China. Banned from the ISS, China has expanded its presence in space with Tiangong space stationcontinuously inhabited since 2022.
Not only does China plan to double its size from three to six modules in the coming years, but it is already opening its doors to international cooperation, as demonstrated by the recent agreement to train and send Pakistani astronauts to the Chinese space station.
With NASA focusing on a business model and deep space exploration, Beijing is strategically positioned as a central player and potential alternative in low orbit, especially for nations seeking to collaborate outside the American framework.
A changing environment. But there is another reason why the United States has focused on the Moon and Mars. Low Earth orbit faces the increasingly critical challenge of space debris. Millions of objects, from dead satellites and rocket upper stages to small undetectable fragments generated by collisions or anti-satellite missile tests.
This debris travels at enormous speeds and represents a constant and potentially catastrophic collision risk for astronauts. The ISS itself has had to carry out numerous evasive maneuvers in recent years. Managing this problem through better tracking systems (especially for small objects), active removal of the most dangerous debris and, above all, prevention and mitigation in the generation of new space debris (such as rapid deorbitation of rocket stages) will be essential to ensure the safety of future crews in the long term.
For now, and for just over 25 years, we continue to inhabit the space. October 31, 2000 was the last day of an era in which humanity was anchored exclusively to the Earth. Since then we have been, without interruption, a species with an extraterrestrial presence. Human permanence off Earth seems assured, but its sustainability will require even more effort and global cooperation.
Image | THAT
A version of this article was published in May 2025
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