NASA
As STS-112 mission specialist, Piers Sellers is pictured on the aft flight deck of the Space Shuttle Atlantis in 2002.
The US space agency confirmed in a statement that Sellers died in Houston, Texas - just a year after being diagnosed with stage four pancreatic cancer in 2015.
Sellers was born in Crowborough, East Sussex, England.
NASA Administrator Charles Bolden said:
"The entire NASA family mourns the passing of scientist and astronaut Piers Sellers.
"Piers was dedicated to all facets of exploration. His curiosity and drive to uncover new knowledge was generously shared with audiences around the world, both from space and in wide travels to reach as many people as possible with an essential understanding of our fragile planet."
You can read the full statement here.
Dr Sellers gained an Ecological Science degree from Edinburgh University in 1976 before eventually gaining his Ph.D. from Leeds University in 1981.
In 1982, he joined NASA as a scientist and eventually became only the third Briton to go into space in 2002.
Learn more about his incredible life and contribution to science: