On Nov. 2, 2000, the International Space Station welcomed its first long-term residents: NASA astronaut Bill Shepherd and Russian cosmonauts Yuri Gidzenko and Sergei Krikalev. Their mission, Expedition 1, marked the beginning of continuous human habitation aboard the station.
Before Expedition 1, NASA had conducted five Space Shuttle missions lasting about a week to help assemble the station and deliver supplies. The first resident crew, however, was scheduled to remain for four and a half months. Rather than traveling aboard a shuttle, the astronauts used a Russian Soyuz spacecraft, the first Soyuz to dock with the space station.
During their stay, the crew unpacked supplies and installed new equipment, including the station’s first solar arrays. They later returned to Earth aboard Space Shuttle Discovery, which delivered the Expedition 2 crew to replace them.
Expedition 1 demonstrated that the International Space Station could support astronauts living and working in orbit. The station was not the first space station, but it went on to become the longest-running one, hosting hundreds of astronauts from around the world.
According to the source, the ISS has maintained a continuous human presence for 26 years. NASA has also stated that the station could be decommissioned in the coming years, but the achievements of its first crew remain an important part of spaceflight history.
Sources: Space.com.