Commander Scott Kelly has just returned from his 340-day mission aboard the ISS. The record breaking mission has seen Kelly and Russian cosmonaut Mikhail Kornienko spend almost a year in space, and scientists hope to gain an insight into what long stays in microgravity do to the body, with views on missions to Mars in the future.
Over the last year, Commander Kelly has not only been in charge of the ISS and conducted important scientific experiments, but he has also been an avid scientific communicator, posting incredible photos on his Twitter page. Here's a selection of his best shots.
This stunning colourful photo was posted by Kelly in February and shows Algeria's Tassili N'Ajjer National Park. NASA/Scott Kelly
In this tweet, Kelly said: "#Bahamas, the strokes of your watercolors are always a refreshing sight." The image of the Caribbean archipelagus was taken last July. NASA/Scott Kelly
This Zinnia plant was the first flower grown in space. The commander snapped this picture in January. NASA/Scott Kelly
"#GoodMorning #Egypt! Your colors never cease to amaze! #YearInSpace " tweeted Kelly after taking this breathtaking picture of the Governorate of Wadi Al-Jadid, Egypt. NASA/Scott Kelly
"Day 207, dusk over the Indian Ocean with a yellow band on the horizon," this tweet read. The yellow band is the light of the Sun reflecting on the atmosphere. NASA/Scott Kelly
Hurricane Patricia was the second most intense tropical cyclone on record and it was responsible for six casualties. Seeing it over Mexico before making landfall, Scott Kelly remarked on how menacing it looked. NASA/Scott Kelly
This incredible picture shows the aurora from last August. NASA/Scott Kelly
Our homes in the cosmos, Earth and the Milky Way are visibile in this beautiful picture. NASA/Scott Kelly
The Alps and the whole italian boot are visibile here through the clouds. He tweeted this in January. NASA/Scott Kelly
A picture of the saltwater lake La’nga Co in Tibet. It's Sanskrit name translates to "lake of the demon", as the lake is devoid of fish and plants. Kelly tweeted this picture in January. NASA/Scott Kelly