# International Space Station The largest structure humans have built in space — a modular orbital laboratory the size of a football field, continuously crewed since November 2000, representing a partnership among [[NASA]], Roscosmos (Russia), ESA (Europe), JAXA (Japan), and CSA (Canada). The ISS is simultaneously the most expensive single object ever constructed (estimated total cost exceeding $150 billion), the longest-running example of post-[[Cold War]] international cooperation, and a case study in how geopolitics complicates scientific collaboration. ## Construction and operation Assembly began in 1998 with the Russian Zarya module and continued through 2011, requiring over 40 assembly flights — most delivered by the [[Space Shuttle]]. The station orbits at approximately 400 km altitude and has hosted over 270 visitors from 21 countries. Research aboard the ISS spans microgravity physics, human physiology (critical for future long-duration spaceflight), materials science, and Earth observation. After the Shuttle's retirement in 2011, crew transportation depended entirely on Russian Soyuz spacecraft for nearly a decade — a strategic dependency that gave Russia significant leverage over American space operations. [[SpaceX]]'s Crew Dragon (first crewed flight May 2020) ended that dependency and shifted the crew-transport function to the commercial sector, making the ISS a linchpin of the government-to-commercial transition in human spaceflight. ## Political dimensions The ISS was conceived partly as a post-Cold War peace dividend — a way to keep Russian rocket scientists employed on cooperative projects rather than selling their expertise to proliferating states. The partnership has been strained by the Ukraine conflict since 2022, raising questions about whether scientific cooperation can or should be insulated from geopolitical confrontation. Russia has announced plans to withdraw from the partnership after 2028. The station is currently approved for operations through 2030, with NASA planning a controlled deorbit using a SpaceX-built vehicle. The transition from ISS to commercial space stations (Axiom Space, Vast, Blue Origin's Orbital Reef) represents the broader privatization pattern the vault tracks: a government-built capability that demonstrated viability, followed by a handoff to commercial operators who captured the value the public investment created. ## See Also - [[Space Shuttle]] — the vehicle that built it - [[SpaceX]] — the current crew transport provider and planned deorbit contractor - [[NASA]] — the lead agency - [[Cold War]] — the geopolitical context that shaped the partnership - [[Space Exploration]] — the broader context