Reflecting on a Quarter-Century of the International Space Station

On Wednesday, the International Space Station (ISS) will celebrate its 25th anniversary since its physical assembly in orbit. The crew aboard the space shuttle Endeavor attached the US-built Unity node to the Russian-built Zarya module, marking the beginning of the modular construction of the ISS. The space station orbits the Earth 16 times every 24 hours at a speed of five miles per second and has been inhabited by researchers for over 23 years. It is the product of five space agencies from 15 countries – NASA, Roscosmos, ESA, JAXA, and CSA.

NASA will hold a live-streamed event with the STS-88 Space Shuttle Mission crew members to celebrate the quarter-century anniversary of the Zarya and Unity modules linking up. The ISS’s official journey began in the early 1990s when the United States’ Freedom and Russia’s Mir-2 space station projects decided to combine their programs and collaborate on a joint mission. The nations signed an agreement in 1993, formalizing the conception of the ISS. The first crewed mission began in 2000, and the US Lab Module was linked to the station in 2001, expanding the station’s onboard living space by 41 percent.

During its time in orbit, the ISS has contributed significantly to research in areas such as disease research, Alzheimer’s, Parkinson’s, cancer, protein crystal growth, cool flames, human muscle atrophy, bone loss, osteoporosis, water purification systems, Bose-Einstein Condensate, and quantum physics studies. The technology developed for the ISS has also been used in agriculture, disaster relief, and aid provision for less developed areas.

The ISS is currently scheduled for decommissioning in January 2031. NASA plans to guide any remaining bits of the space station into a remote area of the South Pacific Ocean. After its decommissioning, the government and commercial orbital labs are expected to take over its work.