Update: Scott Kelly and Mikhail Kornienko, along with third crewmember Sergey Volkov, successfully landed in Kazakhstan at 11:26 pm Eastern time.
Today, NASA astronaut Scott Kelly will squeeze into a Soyuz capsule and leave the International Space Station for the first time in just less than a year (well, not counting any space walks along the way). It’s a historic moment: When Kelly hits the ground, he’ll have completed the longest stay in space ever, along with his Russian counterpart, cosmonaut Mikhail Kornienko.
You’ll want to watch along. Kelly’s farewell begins at 4:15 pm Eastern time, and the hatch on the Soyuz closes at 4:40 pm, according to NASA. After a bit of a wait, the spacecraft will undock at 8:05 pm. Deorbit burn will occur at 10:32 pm, and landing is scheduled for 11:25 pm. It’s not all over after the landing: Scientists will be comparing data from Kelly’s year in space to his twin brother Mark’s vitals, taken down on Earth (read more here about that effort). Their differences should help NASA understand just how much of an impact space has on the human body—and maybe help them plan for a long-term Mars mission. Until then, though, just watch and wait for a safe landing.