Astronaut Scott Kelly To Leave NASA After Record-Breaking Stay At ISS

After a record-breaking 340-day stay at the International Space Station (ISS), astronaut Scott Kelly announced his retirement from NASA effective on April 1. The 52-year-old astronaut said he will still continue participating in ongoing medical research to study the effects of long-term space travel to the human body.

Upon arriving on Earth from the ISS after traveling some 143,846,525 miles around the Earth, Kelly immediately underwent a battery of tests to see how space has affected his body.

"Our universe is a big place, and we have many millions of miles yet to explore. My departure from NASA is my next step on that journey," Kelly posted in Facebook on March 12.

"I remain ever committed and dedicated to the service of human exploration and advancement whether in space or on Earth," he added.

Scott Kelly went back to Earth with two other crew members, Mikhail Kornienko and Sergey Volkov, inside the Soyuz TMA-18M spacecraft on the evening of March 1. Three crew members were left on the ISS until their mission ends in June.

Astronauts Tim Kopra, Tim Peake and Yuri Malenchenko are continuing their mission on the ISS conducting experiments and maintenance. Three new crew members, Jeff Williams, Oleg Skripochka and Alexey Ovchinin, are set to launch on March 18 to join the others on the ISS.

Kelly spent 159 days aboard the ISS in 2010 to 2011. In total, he spent 520 days in space, making him the most experienced American astronaut moving him up to rank 17 in the world. Kornienko is ranked 18^th with 516 days over two flights to the ISS.

"This year in space mission was a profound challenge for all involved that also gave me a unique perspective and a lot of time to reflect on what my next step should be on our continued journey to help further our capabilities in space and on Earth. I am very proud of what my NASA colleagues and our partners around the world have accomplished together," Kelly said.

"I am grateful for the remarkable twenty years spent as an astronaut with this agency and deeply honored to have served four times in the most unique humbling place off the planet: in space," he added.