NASA astronaut Scott Kelly and Roscosmos cosmonaut Mikhail Kornienko return to Earth after a yearlong mission at the International Space Station.

The National Aeronautics and Space Administration is an independent agency of the US federal government responsible for the United States's civil space program, aeronautics research and space research. Established in 1958, it succeeded the National Advisory Committee for Aeronautics (NACA) to give the American space development effort a distinct civilian orientation, emphasizing peaceful applications in space science. It has since led most of America's space exploration programs, including Project Mercury, Project Gemini, the 1968–1972 Apollo program missions, the Skylab space station, and the Space Shuttle. Currently, NASA supports the International Space Station (ISS) along with the Commercial Crew Program and oversees the development of the Orion spacecraft and the Space Launch System for the lunar Artemis program.

Scott Joseph Kelly is an American engineer, retired astronaut, and naval aviator. A veteran of four space flights, Kelly commanded the International Space Station (ISS) on Expeditions 26, 45, and 46.

The State Corporation for Space Activities "Roscosmos", commonly known simply as Roscosmos, is a state corporation of the Russian Federation responsible for space flights, cosmonautics programs, and aerospace research.

Mikhail Borisovich Kornienko is a Russian cosmonaut who has undertaken multiple missions to the International Space Station (ISS).

The ISS year-long mission, also called the One-Year Mission, was an 11-month-long scientific research project aboard the International Space Station, which studied the health effects of long-term spaceflight.