Norishige Kanai: International Space Station Astronaut Didn't Really Grow 3.5 Inches in Space

Earlier this week, Japanese astronaut Norishige Kanai reported a mysterious growth spurt since his arrival at the International Space Station. While growing slightly taller is common in space travel, Kanai reported a massive increase of 3.5 inches in only three weeks.

Now, he says, this surprising growth was nothing more than an measuring error.

1_10_Norishige Kanai Norishige Kanai waves at a send-off ceremony in Kazakhstan, December 17, 2017. Kirill Kudryavtsev/AFP/Getty Images)

“My height’s been measured here in space and somehow, somehow, I’ve grown 9cm (3.5 inches)! In only three weeks I’ve really shot up, something I haven’t seen since high school,” he originally tweeted.

He joked: “This makes me a little worried that I might not be able to fit in the Soyuz seats for our return.”

Stretchy spines

On Earth, the force of gravity puts pressure on our spines and makes us shrink very slightly during the day. While we sleep horizontally, our squashed spines can unfurl back to their morning height.

On the International Space Station, the effects of gravity are reduced and the spine can extend further. This usually only accounts for an inch or so of growth, which will return to normal back on Earth.

Fake news

After an influx of media interest—and questions from his captain—Kanai decided to remeasure himself to find out how tall he had actually become. This time round he was just less than an inch taller than originally believed.

Kanai tweeted: “This mis-measurement appears to have become a big deal, so I must apologize for this terrible fake news … It appears I can fit on the Soyuz, so I‘m relieved.”

Kanai still has some time to stretch out in space, however. He is due to return to Earth in April, giving him three months for another spurt.