2 spacemen headed home after year aloft

“Physically, I feel pretty good”, Kelly said at a news conference days before his return.

It’s kind of like I’ve been in the woods camping for a year, with regards to hygiene. This afternoon (March 1) at 4:15 p.m. EST (2115 GMT) the trio will bid farewell to the other astronauts and begin the process of closing the hatch of their Soyuz craft – and you can watch that process live here on Space.com.

In this January 21, 2016 photo made available by NASA, one-year mission crew members Scott Kelly of NASA, left, and Mikhail Kornienko of Roscosmos their 300th consecutive day in space.

They are set to undock several hours later, at 0105 GMT Wednesday. Here are five of his best snaps to get you amped up for part one of A Year In Space, which will air Wednesday, March 2 at 7 p.m.

He’s also been the ideal test subject to evaluate the physical and emotional effects on long-duration space flight. While staying a year in space is a feat in and of itself, what really have scientists excited are the implications for the mission to Mars. Kelly has more than 9,39,000 followers on Twitter, and is extremely popular on Instagram for his incredible photography of earth and other celestial bodies from space.

Because humans evolved under the constant pull of Earth’s gravity, experiencing weightlessness for an extended period of time has some significant effects on the body, including decreased bone density, muscle atrophy, impaired blood flow, and alterations to the shape of the heart.

He has spent nearly a full year on the worldwide space station, setting a record for an American astronaut. Kelly will then be flown to NASA’s Johnson Space Center in Houston, where, after a brief rest, he’ll be examined by a bevy of scientists itching to examine him and gather samples.

Astronauts must instead wash with wet towelettes and use a toilet equipped with a suction tube. “It’s a little alarming visually”, astronaut Doug Wheelock, who has traveled in the Soyuz, told ABC News a year ago.

Among the first tests planned for Kelly upon his landing are jumping up from a prone position and standing for three minutes, running a mini-obstacle course and walking a straight line.

Kelly spent 125 more days in space than the closest USA contender.