Last week, NASA astronaut Scott Kelly returned to earth after his 340-day stint on the International Space Station (ISS). But, the record-breaking astronaut wants to go back to the space station. Why?

During his four missions to the ISS, Kelly has spent about 520 days in space. While addressing reporters on March 4, the 52-year-old veteran astronaut said time has come to send someone less experienced from the US space agency to the space station. Kelly also said that he wants to visit the space station again, and if he gets a chance, he will fly on a commercial spacecraft.

Kelly also said that even his brother veteran shuttle astronaut Mark Kelly is still holding out hope to fly for space missions. Like Scott Kelly, his twin brother, Mark, was also a part of NASA’s one year mission to see how human body behaves in long-duration space mission, but he was taking part in the study from earth.

“We have so many talented people in our astronaut office. There's no reason to fly me again. Fly somebody else who hasn't had as much opportunity to do it. But I don't think I would ever say I am absolutely, 100% done”, Kelly said in a statement.

Kelly returned to earth on March 1 along with two Russian cosmonauts after spending 340 days aboard the ISS. He broke previous American astronomy records by living 340 continuous days in space. Russian cosmonaut Mikhail Kornienko was also part of one-year mission to study microgravity’s effects on human body during long durations.

Currently, Kelly is undergoing a recovery period. Recently, he said that his body is re-adjusting to Earth’s gravity. He also revealed that his skin is feeling sensation of burning when he sits for long periods.