Aleksandr "Sasha" Yuriyevich Kaleri is a Russian cosmonaut and veteran of extended stays on the Mir Space Station and the International Space Station. Kaleri has most recently been in space aboard the ISS serving as a flight engineer for the long duration Expedition 25/26 missions. He has spent the fourth-longest time in space of any person, the longest time in space of any currently active cosmonaut, and the longest time in space of any person not born in what is now Russia.