Yesterday, we watched sadly as NASA astronaut Scott Kelly handed over command of the International Space Station to Tim Kopra as his #YearinSpace came to a "bittersweet" end. Now it's time for Kelly and cosmonaut Mikhail Kornienko, who he's spent the past 340 days with, to head home, along with cosmonaut Sergey Volkov. You can watch the whole thing on the live stream above, kicking off from 3.10pm EST (7.10am AEST), with farewells and final hatch closure scheduled for around 4.15pm EST (8.15am AEST).

And although the mission is ending, the science is only just beginning. Kelly will return to Earth in a Soyuz spacecraft tomorrow - a harrowing plummet that takes less than 3.5 hours - and involves the capsule burning through Earth's atmosphere at speeds of around 230 metres per second, before launching parachutes and coming to a somewhat easy landing in Kazakhstan on Tuesday night.

Here's how that looked when Canadian astronaut Chris Hadfield landed:

After that landing, you'd probably be ready for a drink. But as soon as Kelly touches down, he has to jump straight up from his lying-down position and stand still for 3 minutes, before attempting a mini-obstacle course and trying to walk in a straight line (and yes, you'll be able to see that live on the feed at the top of this page).

He'll then report to NASA in Houston the next morning, so more tests can begin. That all sounds pretty cruel for a guy who hasn't felt Earth's gravity for 340 days, but it'll show researchers whether astronauts will be able to get going as soon as they land on Mars, or whether they'll need some down time.

After all, the purpose of the Year in Space mission was to help scientists figure out how long periods of time in space affect the human body. And to assist in the process, Kelly's twin brother, Mark, stayed on Earth as a 'control subject', so doctors could compare their vitals.

"I think we'll learn a lot about longer-duration spaceflight and how that will take us to Mars someday," Kelly said last week in his final press conference from on board the ISS. "So I'd like to think that this is another of many stepping stones to us landing on Mars sometime in our future."

While you're waiting for the live stream above to get to the good parts, don't worry, we've put together some of our favourite Scott Kelly moments and photos from the past #YearinSpace for you to enjoy below. You can also check out this NASA story on all the ways Kelly will have to adjust to life back on Earth.

It was one small bite for man, one giant leap for #NASAVEGGIE and our #JourneytoMars. #YearInSpace #lettuce #spacegrown #veggies #harvest #foodie #tasty A video posted by Scott Kelly (@stationcdrkelly) on Aug 10, 2015 at 10:45am PDT

Cool frozen lake in #Himalayas! #YearInSpace #cool #frozen #lake #space #spacestation #iss #earth A photo posted by Scott Kelly (@stationcdrkelly) on Jan 9, 2016 at 9:10am PST

Lights of #HoChiMinhCity #Saigon #Vietnam. #YearInSpace #lights #earth #night #space #spacestation #iss A photo posted by Scott Kelly (@stationcdrkelly) on Feb 15, 2016 at 1:46pm PST

Gave myself a flu shot in space today for @ISS research. Your turn, @shuttlecdrkelly! A photo posted by Scott Kelly (@stationcdrkelly) on Sep 24, 2015 at 11:58am PDT

#OTD in 1983 Sally Ride became the 1st American woman to fly in space. She inspired all of us. #YearInSpace #nasa #shuttle #ridesallyride #tbt #history A photo posted by Scott Kelly (@stationcdrkelly) on Jun 18, 2015 at 8:53am PDT

#Aurora I don't think I will ever see another quite like you. #YearInSpace #solarstorm #space #iss #photo A photo posted by Scott Kelly (@stationcdrkelly) on Jun 23, 2015 at 12:56pm PDT

Huge thanks to all that made this beautiful launch possible. #YearInSpace A photo posted by Scott Kelly (@stationcdrkelly) on Mar 27, 2015 at 9:09pm PDT