On October 31, 2000, the Soyuz TM-31 spacecraft was launched from the Baikonur Cosmodrome in Kazakhstan. The mission carried three astronauts—two Russian cosmonauts and one American astronaut—to the International Space Station (ISS). This launch marked the beginning of Expedition 1, the first long-duration crew to inhabit the ISS. Since the arrival of this crew, the ISS has been continuously occupied by humans, establishing an ongoing human presence in low Earth orbit. The ISS is a multinational collaborative project involving NASA (United States), Roscosmos (Russia), ESA (European Space Agency), JAXA (Japan Aerospace Exploration Agency), and CSA (Canadian Space Agency). The station serves as a microgravity and space environment research laboratory, supporting scientific research, technology development, and international cooperation. As of 2024, there has not been a single day since October 31, 2000, when all humans have been solely on Earth, due to the ongoing rotation of crews on the ISS.