After spending nearly a year in the International Space Station, American astronaut Scott Kelly of the National Aeronautics and Space Administration (NASA) has returned to Earth standing tall, literally.

Kelly has set a space record after spending 340 days floating 250 miles above our planet. He landed back to Earth in Kazakhstan last Tuesday night.

In this amount of time, the NASA astronaut orbited Earth 5,400 times and witnessed nearly 11,000 sunsets, according to a report by NBC News.

If the amount of time he spent in space in this mission and his other missions were to be totalled, Kelly would have spent 520 days outside planet Earth—another record time.

The American space voyager recalled how limited his movements were in space, although he was technically in an immensely vast galaxy.

"Probably almost half the time I've been here — between sleeping and working on the computer, I've spent in a box the size of a phone booth," Kelly said in earlier an interview with NBC News.

He added that there is one thing he is looking forward to doing after almost an entire year in space: jumping into a swimming pool in his house in Houston.

Kelly, however, will have to be closely monitored by NASA doctors for a year to observe the effects of his extended mission in space on his body. The American astronaut nevertheless said he "feels pretty good" upon returning to Earth.

One interesting initial finding about Kelly's health is that he grew two inches during his latest space adventure. His height was compared to his identical twin brother, Mark, a former NASA astronaut who spent last year with his feet planted on terra firma.

Why exactly Kelly grow? In a separate article, Dr. Felix Gussone, an associate medical producer with NBC News, explained that it's because of the gravitational differences between Earth and space, which had an effect on the astronaut's spinal column.

"Astronauts get a bit taller in space because of the disks of the spinal column: On Earth, the disks are slightly compressed due to gravity. In space, that compression is no longer present causing the disks to expand. The result: the spine lengthens, and the astronaut is taller," Gussone explained.

He added that Kelly is also expected to have a messed up body clock, weak muscles and brittle bones upon his return to Earth from his space mission.