Japanese astronaut Norishige Kanai said Monday on Twitter that he is 3½ inches taller since arriving at the International Space Station on Dec. 19. Weightlessness has that effect: Without gravitational force compressing the spine, fluid between the discs fluctuates as they temporarily expand, like a coiled spring unspooled from the top.
“Good morning, everyone. Today I share some serious news. Since coming to space, I have grown 9 centimeters. This is the most I’ve grown in 3 weeks since junior high school,” Kanai wrote.
Three and a half inches is a notable height difference. NASA has said about two inches of growth is typical and expected in space.
“Nine centimeters is a lot, but it is possible, knowing that every human body is different,” said Libby Jackson, a program manager for the United Kingdom Space Agency, the BBC reported. . .
“I am a little worried I won’t fit in my seat on the return trip on Soyuz,” Kanai said, though he was probably joking. Polk said the spacesuits and seat liners inside the spacecraft were designed with fluctuating bodies in mind, including expanded spines. He and others are not concerned about Kanai squeezing into the seat, each one fitted with a liner customized for and molded to the body of each astronaut and taken aboard the Soyuz to ensure a tight fit during the violent reintroduction to gravity. (Read more about the Japanese Astronaut HERE.)