Zarya launches, beginning construction of the International Space Station
A Russian-built, American-funded module becomes the ISS's first piece
Quick facts
- Agency
- NASA (funded) / Russia (built)
- Launch date
- 20 November 1998
- Builder
- Khrunichev State Research and Production Space Center
- First connection
- 6 December 1998 (Unity module)
What happened
The Zarya module, whose name means 'sunrise,' launched on 20 November 1998 aboard a Russian Proton rocket, becoming the first component of the International Space Station placed in orbit. Zarya was built by the Khrunichev State Research and Production Space Center in Moscow under a NASA contract, making it a Russian-built module that counted as a US contribution to the station. On 4 December 1998, the space shuttle Endeavour launched carrying Unity, the first American-built module, and on 6 December the crew of mission STS-88 connected Unity to Zarya in orbit, formally beginning ISS assembly. Zarya's job in these early years was to provide the station's initial power, propulsion, and guidance while later modules were added.
Why it matters
The Zarya-Unity connection marked the first physical assembly of what would grow into a station involving five space agencies and dozens of countries, replacing Mir as the primary venue for long-duration human spaceflight research and eventually surpassing Mir's own continuous-occupancy record in 2010.
How we know
NASA's own module page for Zarya documents the launch date and its role in the station's early power and propulsion; a separate NASA image article on the beginning of ISS assembly independently corroborates the Unity connection date and STS-88 crew's role.
Sources
- NASA. Zarya Module · Primary source (author-declared)nasa.gov · Cited as a "primary" source (no stronger domain match). · Link is live and its text matches the event's key terms (Jul 2026)
- NASA. Dec. 6, 1998, International Space Station Assembly Begins · Primary source (author-declared)nasa.gov · Cited as a "primary" source (no stronger domain match). · Link is live and its text matches the event's key terms (Jul 2026)
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