And despite the astronauts being described as "stranded" they never really were.

Throughout their mission there have always been spacecraft attached to the space station to get them - and the rest of those onboard - home if there was an emergency.

Now the astronauts have arrived home, they will soon be taken to the Johnson Space Centre in Houston, Texas, where they will be checked over by medical experts.

Long-duration missions in space take a toll on the body, astronauts lose bone density and suffer muscle loss. Blood circulation is also affected, and fluid shifts can also impact eyesight.

It can take a long time for the body to return to normal, so the pair will be given an extensive exercise regime as their bodies re-adapt to living with gravity.

British astronaut Tim Peake said it could take a while to re-adjust.

"Your body feels great, it feels like a holiday," he told the BBC.

"Your heart is having an easy time, your muscles and bones are having an easy time. You're floating around the space station in this wonderful zero gravity environment.

"But you must keep up the exercise regime. Because you're staying fit in space, not for space itself, but for when you return back to the punishing gravity environment of Earth. Those first two or three days back on Earth can be really punishing."

In interviews while onboard, Butch and Suni have said they were well prepared for their longer than expected stay - but there were things they were looking forward to when they got home.

Speaking to CBS last month, Suni Williams said: "I'm looking forward to seeing my family, my dogs and jumping in the ocean. That will be really nice - to be back on Earth and feel Earth."