Expedition 70 was the 70th long-duration expedition to the International Space Station. The expedition began with the departure of Soyuz MS-23 on 27 September 2023 with Danish astronaut Andreas Mogensen taking over the ISS command from Russian cosmonaut Sergey Prokopyev in Expedition 69. It ended with the departure of NASA astronaut Loral O'Hara on Soyuz MS-24 on 6 April 2024.

Soyuz MS-23 was an uncrewed Russian Soyuz spaceflight that launched from Baikonur on 24 February 2023 to the International Space Station to replace the damaged Soyuz MS-22 spacecraft for landing that NASA astronaut Francisco Rubio and Roscosmos cosmonauts Sergey Prokopyev and Dmitry Petelin launched onboard on 21 September 2022 and had a coolant leak on 14 December before returning to Earth uncrewed on 28 March 2023.