Expedition 64 was the 64th long-duration expedition to the International Space Station (ISS) that began on 21 October 2020 with the undocking and departure of Soyuz MS-16. The expedition started with the three crew members who launched onboard Soyuz MS-17 and reached its full complement with the arrival of SpaceX Crew-1, the first operational flight of NASA's Commercial Crew Program (CCP). As Crew-1 consists of a crew of four instead of three like the Soyuz, Expedition 64 marks the beginning of operations for crews of seven on the ISS. In the final week of the mission, Soyuz MS-18 and its three person crew joined the mission. The expedition ended on 17 April 2021 with the departure of Soyuz MS-17.

Soyuz MS-17 was a Soyuz spaceflight that was launched on 14 October 2020. It transported three crew members of the Expedition 63/64 crew to the International Space Station. Soyuz MS-17 was the 145th crewed flight of a Soyuz spacecraft. The crew consisted of a Russian commander and a Russian and American flight engineer.