In pictures: astronaut Scott Kelly's year in space
Former NASA astronaut Scott Kelly's year in space was a momentous occasion for human spaceflight. Here are some of the incredible photos captured along the way.
On 2 March 2016 former NASA astronaut Scott Kelly and cosmonaut Mikhail Korniyenko landed back on Earth after a year spent living and working on the International Space Station.
The purpose of this 'One-Year Mission' was to test the psychological and physical effects on the human body of a year in zero gravity.
Along the way Kelly managed to capture a wealth of photos of both life onboard the ISS and the cosmos just outside his space station window.
His new book Infinite Wonder: An Astronaut's Photographs from a Year in Space is a collection of images revealing the story behind this 342-day journey in Earth orbit.
Below is a selection of some of the incredible photos taken during Kelly's year in space.
Read an extract written by Kelly by scrolling below the gallery.
Infinite Wonder is published in the UK by Doubleday. Images used with permission.
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"My first flight into space was aboard the Space Shuttle Discovery in December 1999 on a mission to repair the Hubble Space Telescope.
There are many things about a first space flight that are surprising: the adrenaline rush of the launch countdown, the roar of the main engines, and the sheer power of the solid rocket motors as they explode with millions of pounds of instantaneous thrust.
These all pale, however, in comparison to the beautiful views of the Earth.
After our eight-and-a-half-minute ride into orbit I glanced outside and saw something on the horizon that seemed completely surreal.
I turned to the commander of the mission, Curt Brown, and asked excitedly, “What the hell is that?” Curt, on his sixth flight into space, replied nonchalantly, “Oh, that’s the sunrise.” I was awestruck.
Later, I would admire the luminescent waters of the ocean, as if someone had taken the most brilliant blue paint and brushed it across a mirror right in front of my eyes.
The bright reds, oranges, and yellows of the deserts were often juxtaposed against the blues of the adjacent waters.
The majestic mountain ranges on the horizon seemingly reached out to touch space. It was clear I would never see something more beautiful than the Earth.
My first flight into space was only eight days. I would have to wait nearly eight years to experience the Earth from space again.
But it wasn’t until my third flight into space in 2010, a long-duration flight to the International Space Station (ISS), launching aboard a Russian Soyuz, that I had the time to fully appreciate my vantage point high above the planet.
On this mission I honed some of the skills that would allow me to capture images of the Earth that I would enhance to emphasize their beauty."
- Scott Kelly
Iain Todd is BBC Sky at Night Magazine's Content Editor. He fell in love with the night sky when he caught his first glimpse of Orion, aged 10.