Today, Scott Kelly breaks NASA’s record for longest single spaceflight of an American astronaut, surpassing the previous record of 215 days held by Michael Lopez-Alegria. Kelly is currently on a one-year mission, scheduled to return to Earth in March 2016.
The qualifying adjectives specifying this is an American record is necessary—Kelly is sharing this year-in-space with Russian cosmonaut Mikhail Kornienko. Between them, Kornienko and Kelly share the record for longest single stay on the International Space Station. All other long-duration spaceflight missions are held by cosmonauts on Mir (topped by Valeri Polyakov at 437.7 days) or on the Salyut 7 space station.
Duration records for single-spaceflights by American astronauts. Image credit: NASA
The longest cumulative time any single astronaut has spent in space is Russian cosmonaut Gennady Padalka who spent 879 days in space over five missions, including time on both Mir and the International Space Station. After launching with Kelly and Kornienko last spring, he broke the record 803 days held by cosmonaut Sergei Krikalev on June 28, 2015. On October 16, 2015, Kelly broke the American record of 382 cumulative days in space held by Michael Fincke . If he returns to Earth on schedule, Kelly will have spent a cumulative 522 days in space over four missions.
Kelly and NASA astronaut Kjell Lindgren completed their first spacewalk on Wednesday, greasing the Canadarm. They will make a second spacewalk on Friday, looking for an ammonia leak. Kelly and Kornienko are expected to return to Earth with Sergey Volkov on the TMA-18M Soyuz spacecraft on March 3, 2016.