International Space Station. Credit: NASA

On Dec. 6, 2023, NASA marked the International Space Station’s 25th year in orbit, lauding the research and collaboration made possible through its construction, the diversity of astronauts who have called it home, and acknowledging its coming demise in the early 2030s.

Since the orbital outpost first became operational in November 1998, it has grown from the size of a school bus to roughly the size of a U.S. football field. Nearly 300 astronauts from 21 countries and various backgrounds have worked and lived on the ISS, conducting more than 3,300 research and education studies.

The ISS was initially made possible through a partnership between the U.S. and the former Soviet Union. In 1998, modules from each country (named Unity and Zarya) were joined by astronauts of the space shuttle Endeavor’s STS-88 mission. Though tensions in the ISS partnership stoked by Russia’s war in Ukraine have threatened its continued operation in the last year, the station will most likely submit to a fate of entropy before any failure of international relations. With signs of aging and decay in the modules, radiators, and central trusses, NASA is looking to decommission the ISS sometime around 2030. The agency hopes to have a functioning replacement up and running by then—likely a commercial space station managed by private aerospace companies.

But the ISS still has life in it yet. Houston-based AxiomSpace is developing new research, habitation, and entertainment modules for the ISS for commercial and private use after 2025. And commercial space missions are continuing to grow.

The knowledge gained through living and working aboard the ISS will have far-reaching impacts on the future of human space travel and habitation. Learning about the effects of space on the human body and how to optimize human health in low-gravity conditions will help establish the first colonies beyond Earth as NASA’s Artemis program begins a new era of lunar exploration.