When Scott Kelly touched ground in the United States on Thursday, he was happy to be home and two inches taller after nearly a year in space.
But his identical twin brother, former astronaut Mark Kelly, has since revealed that Scott is now back to his normal height, CNN reported.
The astronaut was greeted by family, NASA colleagues and Vice President Joe Biden's wife, Jill, when he landed in Houston in the wee hours.
“It’s been a long trip,” Kelly said.
“When I left here in February I was 50 and now I’m 52. It’s great to be back in Texas, on U.S. soil. It’s an unbelievable feeling to be back here on planet Earth," he said.
Biden welcomed him with beer and a apple pie. "Nothing's more American than that," she said.
Kelly, whose identical twin Mark is a retired astronaut, is now two inches taller than his brother. But that height gain will be short-lived, NASA officials said.
His spine expanded while living in his gravity-free temporary home, but will go back to its usual length after living back on Earth, they said.
And on Friday, his twin brother Mark revealed to CNN that Scott had already lost those new inches.
Scott and Mark are participating in a NASA study to document changes to Scott's body caused by living in space. Because the twins share extensive similarities in body and cell structure, scientists will be able to chart any differences to Scott's biological and mental makeup.
So both can look forward to being poked and prodded for several more months.
Scott Kelly said he couldn't wait to swimming in his Houston pool, which he promptly did upon returning home.
He jumped in with all his clothes on.