Expedition 46 Commander Scott Kelly of NASA, and Mikhail Kornienko and Sergey Volkov of Roscosmos landed their Soyuz TMA-18M spacecraft in Kazakhstan at 11:26 p.m. EST. Russian recovery teams will help the crew exit the Soyuz vehicle and adjust to gravity after their stay in space.

Kelly and Kornienko launched to the space station on March 27, 2015, for their one-year mission. The pair’s return on March 1 marks the end of 340 days aboard the space station and almost 143 million miles during their time in space, roughly the same average distance between Earth and Mars.

With Kelly, Kornienko and Volkov landing in Kazakhstan, Kelly has logged 520 days in space on two flights, the first of which was on space shuttle mission STS-103 in 1998. Kornienko has spent 516 days in space on two flights, the first of which was on Expedition 23/24 in 2010. Volkov arrived at the station on September 4 and has spent 548 days in space on three flights, the first of which was in 2008.

Expedition 47 Commander Tim Kopra of NASA, Yuri Malenchenko of Roscosmos, and Tim Peake of ESA (European Space Agency) remain aboard the station to continue research and maintenance. The remainder of the Expedition 47 crew, NASA astronaut Jeff Williams and Russian cosmonauts Oleg Skriprochka and Alexey Ovchinin, is scheduled to launch from Baikonur, Kazakhstan, on March 18.

The one-year mission will provide new insights into how the human body adjusts to weightlessness, isolation, radiation and stress of long-duration spaceflight. The science will continue for months and years as the data are collected and analyzed, an important step in the first phase of NASA’s efforts to prepare humanity for the journey to Mars. Such Earth-reliant exploration will lead to more complex operations in orbit around the moon where NASA will demonstrate, advance, and validate the capabilities and technologies we will need to send humans to Mars.